Australia, Korea, and the rise and fall of middle powers
Washington’s build-up toward possible military action in Venezuela and Iran has attracted concern that the attacks are part of an irreversible decline. For its distant middle power partners, this raises a question: must middle powers fall when their patron does?
Paul Kennedy’s The Rise and Fall of the Great Powers traces how great powers expand, overextend, and decline. His analysis rests on five principles that fit contemporary America: uneven economic growth, the nexus between wealth and power, the dangers of overextension, the lag between economic and military capacity, and the decisive role of productive strength in war.
Middle powers also experience these forces—but with one crucial addition: the constraints and opportunities of strategic alliances with a great power patron.
Australia and South Korea share similarities in economic size, military capacity, alliance structures, and strategic weights—the former as a strategic rear area or logistical base of operations, and the latter as a strategic pivot. As some authors have argued, they can be thought of as the northern and southern anchor points of the Indo-Pacific.
They are both clear beneficiaries of the U.S.-led international order. Australia’s prosperity came through successive natural resource export booms coupled with a conducive international environment resulting from close relationships with first, the U.K., and later the U.S. South Korea’s ascent from the ashes of war to industrial powerhouse was achieved under protection within a global trading order built by and sustained by the U.S.
Venezuela and Iran lie far from the immediate interests of Canberra or Seoul (also far from any direct threat to Washington!). Yet, as allies of the United States, they will be called on to play a role.
They will soon face the test of how to best respond as the old locomotive behind the international order from which they benefited, steams toward a rickety bridge. How will Canberra and Seoul react?
Australia and Korea in Paul Kennedy’s shadow
Kennedy’s criteria to assess decline in great powers include uneven economic growth, the nexus between wealth and power, the dangers of overextension, the lag between economic and military capacity, and the decisive role of productive strength in war. This applies equally to middle powers. Australia and South Korea are in different stages of decline.
Kennedy begins with the reality that global growth is uneven—some states rise faster than others, reshaping the hierarchy of power. Australia’s economy has grown steadily in nominal terms, but structurally it has become narrower: dominated by resource exports and increasingly dependent on China’s demand. Its once-diverse industrial base has atrophied. South Korea, meanwhile, remains dynamic but faces its own headwinds: slowing demographics, heavy reliance on semiconductor exports, and intensifying technological competition from both the U.S. and China.
Both economies are exposed to external cycles, but while Australia’s vulnerability is commodity-driven, Korea’s is technology-driven—two different symptoms of a similar relative slowdown.
Kennedy’s second criterion is the linkage between economic capacity and strategic weight. For Australia, wealth no longer translates cleanly into power: its defense industry is limited, and much of its national wealth is held in financial and resource sectors with little military utility. South Korea, in contrast, still converts wealth into hard power more effectively, sustaining one of the world’s largest standing militaries and an advanced defense industry (with highly significant sales to Australia). Yet its strategic autonomy remains constrained by alliance dependency and the risk of entanglement.
Both countries are discovering that prosperity does not automatically yield leverage when security policy is outsourced.
Third is overextension. The classic trap of stretching commitments beyond means—is evident in both middle powers, though in different forms. Australia’s alliance entanglements and its embrace of AUKUS have committed it to a high-cost technological and strategic agenda that exceeds its industrial base. South Korea, on the other hand, is overextended in security geography: tied to defending the peninsula while drawn into global supply-chain politics and Indo-Pacific alignments.
In both cases, strategic ambition is racing ahead of sustainable resources, echoing Kennedy’s warning that overreach precedes decline.
Fourth, Kennedy observed that a lag often appears between economic vitality and military reach. Australia, even as it enjoyed decades of growth, underinvested in defense manufacturing and regional diplomacy, leaving it strategically hollow just as its economy began to slow. Now it seeks to build capability precisely as fiscal and demographic limits set in. South Korea exhibits the reverse: it built military power early but now struggles to maintain growth rates that can sustain that level of armament and technological edge.
Each is caught on opposite sides of the same temporal lag between wealth and force.
Finally, Kennedy saw productive capacity—the ability to mobilize industrial strength—as the decisive measure of resilience. Australia’s industrial base has been hollowed out; its supply chains are long and foreign-controlled. In a prolonged crisis, its endurance would depend almost entirely on allies. Its submarines will even more than likely not be fully independent. South Korea still retains formidable productive strength, but its wartime resilience would be threatened by its geographic exposure and dependence on maritime trade routes.
Now imagine Australia and South Korea as two carriages hitched to that old locomotive charging down the tracks.
Australia is the comfortable carriage near the engine, warmed by the illusion that proximity equals control. It has grown accustomed to the rhythm of the train, believing that loyalty keeps it safe. South Korea rides farther back — the carriage built later, hitched to the train by necessity, not sentiment. Its passengers are alert to every jolt, aware that a derailment up front could send shockwaves down the train. Both are pulled by the same engine, but only one seems to notice the strain in the tracks ahead.
The alliance variable
In the way their alliances were devised, negotiated, and sustained, Australia and South Korea have had fundamentally different relationships to the U.S.
Australia’s alliance with the United States was born out of cultural alignment as much as existential necessity. The ANZUS Treaty of 1951 formalized what was already an instinctive connection — an English-speaking settler society seeking security through racial, linguistic, and ideological familiarity. The stickling point in negotiations was the inclusion of other states. The U.S. wanted more, Australia wanted less.
South Korea’s alliance, by contrast, was forged in blood and occupation. As a continental-maritime pivot at the edge of Eurasia, control over the Korean Peninsula gave the U.S. an advantage in the emerging Cold War. The 1953 Mutual Defense Treaty was not an act of voluntary alignment but a survival pact concluded under wartime dependency. The sticking point in negotiations was how much autonomy South Korea would retain over its own defense and military forces, especially regarding U.S. operational control and the geographical scope and conditions of the American security guarantee.
For Australia, the alliance has always been pre-emptive rather than reactive, binding Australia to U.S. strategic priorities well beyond its region. Canberra has often acted as an auxiliary power, deploying forces to distant American wars — Vietnam, Iraq, Afghanistan — less to address direct threats than to maintain credibility in Washington. The alliance thus functions as a form of externalized identity politics: a guarantee that Australia remains inside the “Anglosphere” even as Asia grows around it.
For South Korea, U.S. troops remained not as guests but as guarantors of national existence, and the alliance became institutionalized through direct command arrangements. It was structural and coercive: the Combined Forces Command ensured that, in any major conflict, operational control passed to an American general. This created both security and constraint — a shield that deterred invasion but limited sovereign maneuver. When South Korea deployed to distant American wars — Vietnam, Iraq, Afghanistan — it did so in transaction for specific benefits.
Over time, these divergent origins have produced distinct alliance psychologies. Australia’s relationship with the U.S. is unquestioning but elective — a habit of loyalty maintained by belief and reinforced through cultural intimacy. South Korea’s is uneasy but inescapable — a bond maintained by fear and proximity rather than affection. Canberra talks of “interoperability” and “shared values,” while Seoul speaks of “extended deterrence” and “conditions-based transfers.”
As the locomotive approaches a rickety bridge — a metaphor for the uncertain future of U.S. power — the two middle powers confront different instincts.
For Australia, the alliance has fused with national identity: to question it is to question who Australians are. For South Korea, the alliance remains transactional — negotiable, conditional, and rooted in circumstance. Identity is hard to change; transactions can be rewritten. So Australia clings tighter as the bridge groans, while South Korea studies the gaps and calculates its next move. One carriage rides on belief, the other on calculation.
When middle powers fall
Some hold on to the fanciful notion that middle powers can somehow band together and that this will solve their ails. There is no middle power revival - just pressing questions. Will Australia once again march in lockstep, convinced that presence equals influence, mistaking obedience for relevance? Will South Korea continue to abstain, choosing stability and economic pragmatism over ideological alignment? Or could Australia and South Korea begin the slow, quiet process of switching sides — not through open defection, but through diplomatic drift, commercial pragmatism, and strategic fatigue?
The real story of decline for middle powers is not collapse but conversion: the steady realization that alliance habits built in another century no longer guarantee safety in this one.
Australia risks becoming a relic — a carriage welded to a locomotive that no longer runs as it once did. South Korea risks disengagement— a carriage wholly detached from the locomotives that run the show. Both will have to decide whether to keep riding the old locomotive off the end of the bridge or attach themselves to a new locomotive and start laying tracks and building bridges that can carry their load.
