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How did the long reign of Emperor Wu turn the Han from a consolidating dynasty into an expansionist empire, and at what fiscal and human cost did his wars, monopolies and Confucian settlement come?

Emperor Wu of Han (141-87 BC) as the climax of the period, including the shift from the heqin marriage-alliance policy to offensive war against the Xiongnu under Wei Qing and Huo Qubing, expansion into the Hexi (Gansu) corridor and the Western Regions (Zhang Qian's missions and the War of the Heavenly Horses), the annexation of Nanyue and northern Vietnam and the conquest of Gojoseon (Korea), the fiscal reforms that paid for the wars (the salt and iron monopolies, the equable-transport and price-stabilisation systems, and the wuzhu currency reform), the adoption of Confucianism as state orthodoxy under Dong Zhongshu and the imperial academy (Taixue, 124 BC), the mounting costs of expansion and Emperor Wu's later self-criticism, and his death in 87 BC

A focused answer to the HSC Ancient History dot point on the reign of Emperor Wu of Han from 141 to 87 BC. His offensive Xiongnu wars under Wei Qing and Huo Qubing, expansion into Central Asia, Nanyue and Korea, the salt and iron monopolies and equable transport, Confucian orthodoxy under Dong Zhongshu, and the fiscal costs of empire.

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  1. What this dot point is asking
  2. The answer
  3. How to read a source on this topic
  4. Historians on Emperor Wu

What this dot point is asking

This section asks you to treat the long reign of Emperor Wu (141-87 BC) as the climax of the Qin and Han period: the moment when a consolidating dynasty became an aggressive, expanding empire. You need the great military expansion, the offensive wars against the Xiongnu under Wei Qing and Huo Qubing, the reach into Central Asia and the Hexi (Gansu) corridor, the annexation of Nanyue in the south and Gojoseon (Korea) in the north-east; the fiscal reforms built to pay for that expansion, the salt and iron monopolies, the equable-transport and price-stabilisation systems, and the wuzhu currency; the adoption of Confucianism as state orthodoxy under Dong Zhongshu and the imperial academy; and the mounting costs of it all, culminating in Wu's own late self-criticism and his death in 87 BC. Strong answers connect these as one story of expansion and its price, not a list of unrelated achievements.

The answer

The reign and its setting

Emperor Wu (Wudi), personal name Liu Che, came to the throne in 141 BC on the death of his father Emperor Jing and reigned until 87 BC, by far the longest reign of the Qin and Han period. He inherited a dynasty made stable and wealthy by the frugal, low-tax "Rule of Wen and Jing", the decades of recovery that followed Gaozu's founding of the Han in 202 BC. That accumulated surplus is what Wu spent. He was also the first Chinese ruler to adopt era names (nianhao), beginning with Jianyuan in 140 BC, a small administrative innovation that signals a reign consciously marking new beginnings.

The reign of Emperor Wu, 141 to 87 BC A vertical timeline of Emperor Wu's reign. It runs from his accession in 141 BC, through the failed Mayi ambush of 133 BC that ended the heqin appeasement of the Xiongnu, the founding of the Taixue in 124 BC as Confucianism became state orthodoxy, the decisive Battle of Mobei in 119 BC, the currency and fiscal reforms of 118 to 117 BC including the wuzhu coin and the salt and iron monopolies, the annexation of Nanyue in 111 BC and the conquest of Gojoseon or Korea in 108 BC, the War of the Heavenly Horses of 104 to 101 BC, the wugu witchcraft affair of 91 BC that destroyed the crown prince, and the Luntai edict of 89 BC followed by Emperor Wu's death in 87 BC. The reign of Emperor Wu, 141-87 BC 141 BC Accession of Emperor Wu (Liu Che) 133 BC Mayi ambush fails; heqin ends, war begins 124 BC Taixue founded; Confucianism as orthodoxy 119 BC Battle of Mobei; Xiongnu driven north 118-117 BC Wuzhu coin; salt and iron monopolies 111-108 BC Nanyue annexed; Gojoseon (Korea) conquered 104-101 BC War of the Heavenly Horses (Dayuan) 91 BC Wugu affair destroys crown prince Liu Ju 89-87 BC Luntai edict of restraint; death of Emperor Wu The Salt and Iron Debate (81 BC) followed, after Wu's death.

Breaking the Xiongnu: from heqin to offensive war

Since Gaozu's near-capture at Baideng in 200 BC, the Han had contained the Xiongnu steppe confederation through heqin ("harmonious kinship"): marrying Han princesses to the chanyu and sending annual gifts of silk, grain and wine to buy peace. Emperor Wu ended this appeasement. In 133 BC he laid the Mayi ambush, a plan to lure the chanyu's army into a trap near the frontier town of Mayi; the trap failed, but it broke the peace and opened decades of open war.

Wu then unleashed repeated large-scale cavalry offensives deep into the steppe, led by two of the most celebrated commanders in Chinese history: Wei Qing, half-brother of Wu's empress Wei Zifu, who first struck the Xiongnu's sacred site at Longcheng in 129 BC, and Wei Qing's brilliant young nephew Huo Qubing, who led daring long-range raids from 121 BC. The campaigns climaxed in the Battle of Mobei in 119 BC, when Wei Qing and Huo Qubing crossed the Gobi Desert and shattered the main Xiongnu forces, driving the chanyu's court far to the north. Huo Qubing, still only in his early twenties, died two years later in 117 BC. The wars did not annihilate the Xiongnu, but they broke their dominance of the northern frontier and turned the strategic balance decisively towards the Han.

Opening the west: the Hexi corridor and the Western Regions

The Xiongnu wars opened the way west. Huo Qubing's campaigns of 121 BC cleared the Xiongnu from the Hexi (Gansu) corridor, the narrow band of oases running north-west from the Han heartland, and over the following decades the Han planted the four Hexi commanderies (Wuwei, Zhangye, Jiuquan and Dunhuang) to hold it. This corridor became the gateway to the Western Regions of Central Asia.

The key figure here is the envoy Zhang Qian. Sent out around 138 BC to seek an alliance with the Yuezhi against the Xiongnu, Zhang Qian was captured and held by the Xiongnu for roughly a decade before escaping and returning in 126 BC. He failed in his original diplomatic mission but brought back the first detailed Han knowledge of the states of Central Asia, opening the trade artery later called the Silk Road. A second mission around 119 BC reached the Wusun. Desire for the prized "heavenly horses" of Dayuan (Ferghana) later drew Wu into the expensive War of the Heavenly Horses (104-101 BC), fought by the general Li Guangli, which secured Han prestige and the horses deep in Central Asia.

Expansion south and north-east: Nanyue and Korea

Emperor Wu expanded on every frontier, not only against the Xiongnu. In 111 BC his armies annexed the southern kingdom of Nanyue, extending Han administration over the far south (modern Guangdong and Guangxi) and into northern Vietnam, organised into new commanderies. In 108 BC Han forces conquered the north-eastern kingdom of Gojoseon (in the Korean peninsula), establishing four commanderies there, of which Lelang was the most important and longest-lasting. By the 100s BC the Han empire stood at its greatest territorial extent.

Emperor Wu's expansion on four frontiers A schematic strategic diagram, not an atlas map. At the centre sits a box for the Han empire under Emperor Wu, based at Chang'an. Four labelled arrows radiate outward. The arrow pointing north reaches a box for the Xiongnu steppe, marking the offensive wars under Wei Qing and Huo Qubing and the Battle of Mobei in 119 BC that drove the Xiongnu north of the Gobi. The arrow pointing west reaches a box for the Hexi corridor and the Western Regions, marking Zhang Qian's missions from 138 BC, the four Hexi commanderies, and the War of the Heavenly Horses of 104 to 101 BC. The arrow pointing south reaches a box for Nanyue, annexed in 111 BC and reaching northern Vietnam. The arrow pointing east reaches a box for Gojoseon or Korea, conquered in 108 BC with four commanderies including Lelang. A caption notes that expansion on all four frontiers is what drove the fiscal reforms. Expansion on four frontiers Han empire under Emperor Wu (capital Chang'an) NORTH - Xiongnu steppe Wei Qing and Huo Qubing Battle of Mobei, 119 BC Xiongnu driven north of the Gobi SOUTH - Nanyue annexed 111 BC far south and northern Vietnam WEST Hexi corridor and Western Regions Zhang Qian, 138 BC horses war 104-101 BC EAST Gojoseon (Korea) conquered 108 BC four commanderies incl. Lelang Expansion on all four frontiers is what drove the fiscal reforms.

Paying for empire: the fiscal reforms

War on this scale devoured the surplus Wu had inherited. The land tax alone could not sustain it, so Wu built an apparatus of state economic intervention, associated above all with the finance official Sang Hongyang. The centrepiece was the state monopolies on salt and iron, established from around 117 BC: because every household needed both, taking over their production and sale gave the throne a vast, reliable revenue independent of the land tax. Wu also reformed the currency, introducing the standardised bronze wuzhu ("five-grain") coin in 118 BC under strict central minting to replace debased private coinages.

In 110 BC Sang Hongyang added the junshu ("equable transport") and pingzhun ("price stabilisation") systems: the state collected regional taxes in kind, shipped goods to where they sold dearest, and bought cheap to sell dear, profiting as a national merchant while smoothing prices. Wu topped these up with a short-lived liquor monopoly, new property taxes on merchants, and the sale of offices and ranks. Together these measures marked a decisive move towards an interventionist fiscal state, and they provoked a lasting ideological quarrel, argued out at the famous Salt and Iron Debate of 81 BC (recorded later in Huan Kuan's Discourses on Salt and Iron, the Yantie Lun), between Confucian reformers who wanted the monopolies abolished and finance officials who defended them as the price of a strong frontier.

Confucianism as state orthodoxy

Emperor Wu also gave the state an official ideology. His court scholar Dong Zhongshu urged, in memorials answering the emperor's policy questions around 134 BC, that the competing "hundred schools" of philosophy be set aside and Confucian classics alone made the foundation of official learning, supplying the throne with a single moral language of the Mandate of Heaven and hierarchical loyalty. Wu acted on the advice in stages: in 136 BC he appointed Erudites (boshi) dedicated to the Five Classics; in 124 BC he founded the Taixue (Imperial University) at Chang'an, beginning with about 50 students; and the xiaolian ("filial and incorrupt") recommendation system tied office-holding to reputation and, increasingly, Confucian learning.

In practice this Confucian veneer sat over administrative machinery that remained heavily Legalist, strict law codes, household registration for tax and conscription, and the salt and iron monopolies themselves, all inherited or developed from Qin methods. Michael Loewe's summary of the mature Han state, "Confucian in appearance, Legalist in substance", captures Wu's settlement exactly: he layered a new ideology over the coercive apparatus of the unified empire rather than replacing it.

The costs of expansion and the end of the reign

By the later decades of the reign the costs had become impossible to ignore. The treasury the monopolies were built to fill was itself strained by the endless campaigns, most extravagantly the War of the Heavenly Horses (104-101 BC). Heavy exactions, the merchant taxes and the sale of ranks fell on a wearied population. The reign then turned on itself: in 91 BC the wugu ("witchcraft") affair, a terror of accusations of black magic at court, spiralled into the destruction of the crown prince Liu Ju, who was driven into a failed revolt and death.

Late in life Emperor Wu made a striking gesture of restraint. In 89 BC, when officials proposed establishing a further military colony far off at Luntai in the Western Regions, Wu refused in the Luntai edict, declining to "weary the empire" with more distant war, a rare note of imperial self-criticism traditionally read as a turn away from expansion. He died in 87 BC, leaving the throne to his young son Liu Fuling (Emperor Zhao) under the regency of Huo Guang, who steered the state towards fiscal retrenchment, the context of the Salt and Iron Debate two years later. The empire Wu left was the largest the Han would ever hold, and the most exhausted.

Emperor Wu's reign at a glance

Date Event Significance
141 BC Accession of Emperor Wu Start of the longest reign of the period
133 BC Failed Mayi ambush Ends heqin; opens war with the Xiongnu
119 BC Battle of Mobei (Wei Qing, Huo Qubing) Xiongnu driven north of the Gobi
138-126 BC Zhang Qian's first mission Opens the Western Regions and Silk Road
118 BC Wuzhu coin introduced Currency reform under central minting
117 BC Salt and iron monopolies State revenue to fund the wars
111 / 108 BC Nanyue annexed; Gojoseon conquered Expansion south and north-east
124 BC Taixue (Imperial University) founded Confucianism institutionalised
89 / 87 BC Luntai edict; death of Emperor Wu Late restraint; reign ends exhausted

How to read a source on this topic

The written evidence for Emperor Wu's reign comes overwhelmingly from two great histories, and knowing their character is half the source-analysis battle. Three reading habits.

First, weigh proximity against motive. Sima Qian's Records of the Grand Historian (Shiji, completed around 91 BC) is near-contemporary and detailed, but Sima Qian was castrated in 99 BC on Wu's authority for defending the general Li Ling, so his account of the emperor and his wars can carry personal grievance and a Confucian scholar's disapproval of aggressive expansion and state monopoly. Ban Gu's Book of Han (Hanshu, later 1st century AD) is fuller and more systematic on the reign's institutions, but was written under the restored dynasty with its own retrospective standpoint.

Second, distinguish an official document from a historian's narrative. Imperial edicts (such as the Luntai edict of 89 BC) and court memorials (such as those defending the monopolies) survive embedded in these later histories. An edict presents the throne's chosen self-image and should never be read as a neutral report of policy; ask what image it was framed to project.

Third, watch for the ideological lens. Much of the tradition judges Wu's monopolies and wars against a Confucian ideal of frugal, benevolent rule, a standard set out explicitly in the later Salt and Iron Debate. That lens is itself evidence of the reign's central tension, but it can flatten a hard fiscal necessity into simple moral failure.

Historians on Emperor Wu

Michael Loewe is the leading modern authority on the Han: he frames the politics of the reign and its aftermath as a contest between a "Modernist" party, favouring expansion, state monopolies and strong central finance (Sang Hongyang), and a "Reformist", broadly Confucian party favouring retrenchment and lighter government, with the Luntai edict and the later Salt and Iron Debate as the hinge between them (Crisis and Conflict in Han China, 1974; The Cambridge History of China, Volume I, edited with Denis Twitchett, 1986). Mark Edward Lewis (The Early Chinese Empires: Qin and Han, 2007) reads Wu's reign as the height of Han imperial power and its overreach at once, the point at which expansion outran the fiscal base. Among the ancient writers, Sima Qian supplies the closest, most detailed testimony, complicated by his punishment, while Ban Gu provides the fuller institutional record. Flag for the lead: the traditional reading of the Luntai edict as genuine "repentance" and a decisive policy turn has been questioned in recent scholarship; present it as the conventional interpretation while noting that its meaning is debated.

Practice questions

Original practice questions graded from foundation to exam level, each with a full worked solution. Try them before revealing the solution.

foundation3 marksOutline the change in Han policy towards the Xiongnu that occurred under Emperor Wu.
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A 3-mark "outline" wants the earlier policy, the turning point, and the new policy, each briefly and accurately stated.

The earlier policy (heqin)
From Gaozu's near-disaster at Baideng in 200 BC, the early Han had managed the Xiongnu confederation through heqin ("harmonious kinship"): sending imperial princesses in marriage and regular gifts of silk, grain and wine to the chanyu to buy peace on the northern frontier.
The turning point
Emperor Wu abandoned appeasement. In 133 BC he attempted the Mayi ambush, a failed plan to trap the chanyu and his army near the border town of Mayi; although the trap failed, it ended heqin and opened decades of open war.
The new policy
Wu launched repeated large-scale offensive cavalry campaigns deep into the steppe, led by generals Wei Qing and his nephew Huo Qubing, culminating in the Battle of Mobei in 119 BC, which drove the Xiongnu court north of the Gobi Desert.

Markers reward the named earlier policy (heqin), the Mayi turning point in 133 BC, and the shift to offensive war under Wei Qing and Huo Qubing.

foundation4 marksDescribe the main fiscal reforms Emperor Wu introduced to pay for his wars of expansion.
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A 4-mark "describe" wants several developed, correctly dated measures.

State monopolies on salt and iron
From around 117 BC, on the advice of finance officials led by Sang Hongyang, the state took over the production and sale of salt and iron, the two commodities every household needed, turning them into a guaranteed source of revenue independent of the land tax.
Currency reform
In 118 BC Wu introduced the standardised bronze wuzhu ("five-grain") coin, minted under central control, replacing debased and privately cast coinages and stabilising the money supply.
Equable transport and price stabilisation
In 110 BC Sang Hongyang established the junshu ("equable transport") system, which collected regional taxes in kind and moved goods to where they sold dearest, and the pingzhun ("price stabilisation") system, under which the state bought cheap and sold dear to level prices and profit from the trade.
Other expedients
Wu also briefly monopolised liquor, sold offices and ranks, and levied new taxes on merchants' property, all to feed the enormous cost of the frontier wars.

Markers reward the salt and iron monopolies, the wuzhu coin (118 BC), the equable-transport and price-stabilisation systems (110 BC), and the link back to funding the wars.

core5 marksSource A (an ExamExplained reconstruction, in the style of a Han court memorial by a finance official): 'Your servant submits that the profits of the mountains and seas, the salt and the iron, should not fall to private families who grow rich while the frontier armies go unfed. Let the office of the state take them, that the campaigns against the Xiongnu may be supplied.' Using Source A and your own knowledge, explain what this type of evidence reveals about how Emperor Wu funded his expansion.
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A 5-mark "explain" needs the source decoded and then supported with accurate own knowledge.

Use the source
Source A shows a finance official arguing that the profits of salt and iron ("the mountains and seas") should be taken from private producers by the state specifically so that "the campaigns against the Xiongnu may be supplied", directly tying the monopolies to the cost of the frontier wars.
Own knowledge: the real policy this reflects
This reflects the salt and iron monopolies Emperor Wu established from around 117 BC under officials such as Sang Hongyang, Kong Jin and Dongguo Xianyang, alongside the wuzhu coin of 118 BC and the equable-transport and price-stabilisation systems of 110 BC, a whole apparatus of state economic intervention built to pay for expansion.
Own knowledge: what it reveals
It reveals that Wu's expansion could not be funded from the ordinary land tax alone, so the state turned itself into a merchant and manufacturer, an interventionist fiscal policy that Michael Loewe associates with the "Modernist" faction at court and that the Confucian "Reformists" later attacked, most famously at the 81 BC Salt and Iron Debate.

Markers reward decoding the source's argument, correct identification of the real monopolies and their dates, and the point that expansion drove an interventionist fiscal state.

core6 marksSource B (an ExamExplained reconstruction, in the style of a late edict of Emperor Wu): 'In former days the officials proposed to send more soldiers far off to Luntai. But to weary the empire further is not the way to nurture the people. From this time let harsh and wearisome campaigns be halted.' Using Source B and your own knowledge, assess the usefulness and limitations of this type of evidence for understanding the costs of Emperor Wu's expansion.
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A 6-mark "assess" needs balanced usefulness and limitations, own knowledge, and a historian.

Content
The source has an ageing emperor rejecting a proposal for further distant campaigns (at Luntai in the Western Regions) on the ground that they "weary the empire" and do not "nurture the people", a rare note of imperial restraint and near-regret.
Usefulness
This type of evidence is genuinely useful because it reflects a documented moment: the Luntai edict of 89 BC, in which Wu declined to expand the war in Central Asia. By then decades of campaigning against the Xiongnu, in the Hexi corridor, against Dayuan (the War of the Heavenly Horses, 104-101 BC), and in Nanyue and Korea, had drained the treasury the monopolies were built to fill, provoked the property taxes on merchants, and contributed to unrest, so an edict acknowledging the human cost fits the fiscal reality.
Limitations
An edict is an official, self-justifying document preserved through the later dynastic histories (chiefly Ban Gu's Hanshu), so it presents the throne's chosen image; it may soften a lifetime of aggressive war into statesmanlike regret. It also captures a single late moment, not the reign as a whole, and historians debate how far it signals a real change of policy as opposed to a rhetorical gesture.
Historian and own knowledge
Michael Loewe long read the Luntai edict as a genuine turn from "Modernist" expansion towards "Reformist" retrenchment, later carried through by Huo Guang after Wu's death in 87 BC, though the strength of that reading is now debated; either way the edict corroborates that expansion had reached the limit of what the fiscal reforms could sustain.

Markers reward balanced usefulness and limitations, the named context (the 89 BC Luntai edict and the cost of the wars), an explicit comment on the bias of an official edict preserved in later histories, and a named historian used as argument.

core4 marksExplain how Emperor Wu made Confucianism the orthodoxy of the Han state.
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A 4-mark "explain" needs the mechanism, not just the label "Confucianism".

The adviser and the argument
Emperor Wu's court scholar Dong Zhongshu argued, in memorials answering the emperor's own policy questions around 134 BC, that the "hundred schools" of philosophy should be dismissed and Confucian classics alone made the basis of official learning, giving the throne a single moral vocabulary of the Mandate of Heaven and hierarchical loyalty.
The institutional steps
Wu acted on this: in 136 BC he established Erudites (boshi) dedicated to the Five Classics; in 124 BC he founded the Taixue (Imperial University) at Chang'an, beginning with about 50 students trained in the Confucian canon; and he linked office-holding to the xiaolian ("filial and incorrupt") recommendation system, so that a Confucian education became the pathway into the bureaucracy.
The reality beneath
Confucian ideology sat over administrative machinery that remained heavily Legalist, strict law, household registration and the salt and iron monopolies, a synthesis Michael Loewe calls "Confucian in appearance, Legalist in substance".

Markers reward Dong Zhongshu's role, the concrete institutions (boshi in 136 BC, the Taixue in 124 BC, xiaolian recruitment), and awareness that Legalist practice continued beneath the Confucian veneer.

exam6 marksSOURCE ANALYSIS. Assess the values and limitations of Sima Qian's Records of the Grand Historian (Shiji) as evidence for the reign of Emperor Wu.
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A 6-mark values/limitations task needs balance, specificity, and a historian.

Origin
The Shiji was completed around 91 BC by Sima Qian, who served Emperor Wu as Grand Historian and Court Astrologer and so wrote as a near-contemporary of the reign, with access to court records and archives.
Values
Its value is exceptional: Sima Qian is a first-hand witness to Wu's court, and his account of the Xiongnu wars, of Zhang Qian's missions to the Western Regions, and of the fiscal debates gives detailed, close-range evidence for the machinery and personalities of expansion (Wei Qing, Huo Qubing, Sang Hongyang). His biographical and treatise structure preserves administrative and economic detail a simple chronicle would omit.
Limitations
Sima Qian was not a neutral observer. In 99 BC he was sentenced to castration for defending the defeated general Li Ling, a punishment authorised by Emperor Wu himself, so his portrayal of the emperor and his wars can carry personal bitterness and veiled criticism. As a Confucian-trained scholar he was also inclined to judge Wu's aggressive expansion and interventionist finance against a moral standard of frugal, benevolent rule.
Historian and corroboration
Modern scholars such as Michael Loewe treat the Shiji as indispensable but read it critically alongside Ban Gu's later Hanshu, weighing Sima Qian's proximity against his motive; the two together, cross-checked, remain the foundation for the reign.

Markers reward origin and proximity, the specific content the Shiji supplies, the explicit motive (the Li Ling affair and Sima Qian's Confucian outlook), and a named historian on how the source is used.

exam25 marksESSAY. 'Emperor Wu's reign was an age of expansion bought at a ruinous cost.' To what extent do you agree with this assessment of the reign 141-87 BC?
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A band-6 essay states a judgement on "to what extent", sustains it with dated evidence, and weaves historiography. This is a PLAN plus a model paragraph.

Thesis
The statement is substantially right but one-sided. Emperor Wu's reign (141-87 BC) was genuinely the climax of the period: he broke the Xiongnu, opened the Western Regions, absorbed Nanyue and Korea, and built an interventionist fiscal and Confucian-bureaucratic state that outlasted him. But these achievements were indeed bought at ruinous cost, an emptied treasury, heavy exactions, and human suffering that Wu himself acknowledged late in life, so "expansion at a ruinous cost" captures the reign only if both halves are weighed together rather than one being used to cancel the other.
Argument line 1: the scale of expansion was real
The shift from heqin to offensive war after the Mayi attempt of 133 BC produced decisive victories, above all the Battle of Mobei in 119 BC under Wei Qing and Huo Qubing, which drove the Xiongnu north of the Gobi. Zhang Qian's missions (from 138 BC) opened the Hexi corridor and the Silk Road; Nanyue was annexed in 111 BC and Gojoseon (Korea) conquered in 108 BC. On any measure the empire reached its greatest extent.
Argument line 2: the reforms were a lasting achievement, not only a cost
To pay for the wars Wu created the salt and iron monopolies (from around 117 BC), the wuzhu coin (118 BC), and the equable-transport and price-stabilisation systems (110 BC), while Dong Zhongshu's Confucian settlement, the Erudites (136 BC) and the Taixue (124 BC), gave the state an enduring ideology and civil service. These outlived him.
Argument line 3: the cost was nonetheless ruinous
The monopolies and merchant taxes reflect a treasury drained by war; the War of the Heavenly Horses (104-101 BC) was hugely expensive; the wugu (witchcraft) crisis of 91 BC destroyed the crown prince Liu Ju; and the Luntai edict of 89 BC has Wu himself refusing further campaigns as a burden on the people. His death in 87 BC left a child emperor under Huo Guang's regency and a policy turn towards retrenchment.
Historiography
Michael Loewe frames the reign as a contest between a "Modernist" party (expansion and state monopolies, Sang Hongyang) and a "Reformist", Confucian party favouring retrenchment, with the Luntai edict as a hinge, though the edict's meaning is now debated. Mark Edward Lewis treats Wu's reign as the height of Han imperial power and its overreach at once. Sima Qian, writing near-contemporaneously (and embittered after 99 BC), and Ban Gu's later Hanshu supply the evidence, each with its own slant.
Model paragraph (line 3)
The clearest sign that expansion carried a ruinous price is that the emperor who drove it ended by disowning it. Decades of campaigning, against the Xiongnu, into Ferghana in the War of the Heavenly Horses of 104 to 101 BC, and across Nanyue and Korea, had emptied the treasury that the salt and iron monopolies were built to fill and forced ever harsher taxes on merchants and the people. By 91 BC the reign was consuming itself: the wugu witchcraft terror drove the crown prince Liu Ju to his death. When, in 89 BC, officials proposed yet another distant garrison at Luntai, Wu refused in an edict lamenting that further war would only "weary the empire". As Loewe argues, that edict marks the exhaustion of the Modernist programme, the point at which even its architect conceded that expansion had reached the limit of what the reforms could sustain.
Conclusion
Wu's reign was an age of expansion, and it was bought at a ruinous cost; but it also built institutions, the monopolies, the coinage, the Confucian bureaucracy, that endured. The verdict, therefore, is a qualified agreement: ruinous in the short term, foundational in the long term.

Marker's note: band 6 answers state a clear verdict on "to what extent", deploy precise dated evidence (133 BC, 119 BC, 118 BC, 111 BC, 108 BC, 89 BC, 87 BC), integrate at least two named historians as argument (Loewe's Modernist/Reformist frame; Lewis on overreach), and include a genuine counter-weight (the lasting reforms) rather than a one-sided list of costs.

ExamExplained