The Unquiet Frontier

1. America's Frontier Alliances are Essential, Not Liabilities.

For the past sixty years U.S. foreign policy has pursued exactly the opposite course, and for good reason.

Strategic necessity. The United States maintains a vital network of alliances with vulnerable states located at strategic global crossroads, choke points, and arteries, often referred to as the "rimland." These allies, though small to mid-sized, are crucial for American power. Critics often view these alliances as liabilities, citing costs and the risk of entrapment in distant conflicts.

Return on investment. However, these alliances have consistently provided a significant return on investment for the U.S. They have been instrumental in:

• Containing and deterring ambitions of large rivals (China, Iran, Russia).
• Suppressing regional conflicts.
• Keeping crucial trade routes open.
• Promoting democracy and the rule of law in historically volatile zones.

Global order's glue. Allies have served as the "glue" of the U.S.-led global order, first by containing the Soviet Union during the Cold War and then by sustaining stability and prosperity in the post-Cold War era. This forward engagement, rooted in the strategy of maintaining a presence in the Eurasian littorals, is a central tenet of U.S. foreign policy, preventing the U.S. from being perceived as unreliable.

2. U.S. Deprioritization of Allies Stems from Deep-Rooted Temptations.

The luxury of choice is, however, also a curse because it introduces doubt about the reliability of the United States as an ally; the wider the spectrum of possible strategic options, the greater the perception of untrustworthiness.

Three temptations. America's tendency to deprioritize alliances is rooted in a sense of safety derived from its unique geographic position, perceived technological superiority, and ideological convictions. These factors create a "luxury of strategic choice" that, paradoxically, can lead to doubts about U.S. reliability among allies.

Drivers of disengagement. Historically, these temptations manifest as:

• Geography: The belief in "free security" behind vast oceans, advocating for hemispheric defense and minimal overseas commitments.
• Technology: Faith in naval power, airpower, ballistic missile defense, or drones as sufficient for security, rendering allies expendable.
• Ideology: Liberal internationalism (harmony of interests) or isolationism (self-balancing world) both suggest limited U.S. intervention is needed.

Current trends. In recent years, this deprioritization has been exacerbated by:

• Fatigue from wars in Iraq and Afghanistan.
• Economic slowdown and fiscal imbalances, shifting focus to domestic issues.
• Allies' perceived "free-riding" on defense spending.
• The "shale gas revolution" reducing U.S. dependence on foreign energy.
  This has led to a "great-power preference" in U.S. policy, seeking accommodation with rivals like Russia and Iran, often at the expense of traditional allies.

3. Revisionist Powers Exploit U.S. Weakness Through "Probing" Tactics.

Sensing an opportunity, they want to revise the regional order, but they are uncertain about the amount of geopolitical leeway they have and therefore the degree of license they can take in safely challenging the status quo.

Testing the waters. In moments of perceived shifts in global power, such as a weakening U.S. commitment, revisionist powers like China, Russia, and Iran engage in "probing" behavior. This involves low-intensity, low-risk tests designed to gauge the leading power's resolve and willingness to maintain influence, without triggering a direct military confrontation.

Key features of probing:

• Low intensity: Actions carefully avoid direct war, often using unmarked units (e.g., Russia's "little green men" in Crimea) or civilian-looking vessels (e.g., China's fishing fleet in the South China Sea) to deny authorship and minimize escalation.
• Low risk, high reward: Probes target strategically important regions in the revisionist's immediate vicinity, where the hegemon's influence is present but not preponderant, maximizing potential gains while minimizing direct confrontation.
• Peripheral/indirect: Probes focus on the outer limits of the rival's power, often targeting its allies, to exploit the "entrapment-abandonment dilemma" and drive a wedge in opposing alliances.

Multiple audiences. Probing serves to:

• Assess the targeted ally's capacity to withstand pressure and potentially push them to sever ties with the U.S.
• Test the U.S.'s reliability and commitment to its allies, forcing it to expend resources and political capital to reassert security guarantees.
• Signal to geopolitical onlookers that the existing great power is in decline, influencing their perceptions of global stability.

4. Allies Respond to Uncertainty with Diverse, Often Dangerous, Strategies.

For states like Israel, Taiwan, and Poland, the diminishing utility of extended deterrence represents a grave national-security problem that, unless somehow mitigated, could eventually pose a threat to their prosperity, political independence, or even continued existence as states.

Weakening deterrence. The perceived weakening of American extended deterrence, coupled with intensifying revisionist probes, compels U.S. allies to re-evaluate their security strategies. They doubt the U.S.'s political will and ability to intervene, especially against "limited war" tactics below traditional deterrence thresholds.

Strategic menu cards. Allies are exploring a range of coping mechanisms:

• Military self-help: The most common response, involving significant increases in defense spending and modernization efforts.
  • Asia: Japan, Philippines, Indonesia, Vietnam are rapidly acquiring advanced weaponry.
  • Middle East: Israel and Gulf states are building long-range strike and anti-ballistic missile defense systems.
  • Central and Eastern Europe: Poland, the Baltic states, and Romania are boosting defense budgets and retooling for territorial defense, moving away from expeditionary warfare.
• Rise of offensive doctrines: Some vulnerable states, like Israel (Dahiya Doctrine) and Finland, are developing offensive strike capabilities to deter larger powers, a trend potentially spreading to Japan, Saudi Arabia, and Poland, with some even considering nuclear weapons.
• Regional caucusing: Allies are forming regional alliances to strengthen collective defenses.
  • Asia: ASEAN is evolving into a mechanism to coordinate opposition to China.
  • Middle East: The Gulf Cooperation Council (GCC) is moving towards a "Gulf Union" with joint military command.
  • Central and Eastern Europe: The Visegrád Group and Nordic-Baltic Group are intensifying defense cooperation against Russia.
• Accommodation strategies: Some allies are hedging their bets by mollifying or accommodating threatening states, avoiding open resistance while maintaining U.S. ties.
  • East Asia: Thailand and Malaysia pursue flexible diplomacy with China.
  • Persian Gulf: Oman and Qatar maintain friendly relations with Iran, acting as intermediaries.
  • Central and Eastern Europe: Bulgaria and Hungary maintain close ties with Russia, sometimes breaking from EU consensus.

Dangerous outcomes. While some balancing is beneficial, accommodation can undermine other allies and potentially lead to bandwagoning. Offensive or nuclear self-help strategies, if unchanneled by U.S. presence, risk regional destabilization and increased conflict.

5. Alliances Offer Crucial Geopolitical Advantages for U.S. Stability.

Only when the United States had found a way to sustainably project its influence in these regions abutting the Eurasian continental core, Spykman reasoned, could it hope to head off future attempts at hegemony at their source and bring to an end the cycle of retrenchment and reentry that had destabilized global geopolitics in the twentieth century.

Geopolitical imperative. As a maritime power, the U.S. faces the grand strategic challenge of preventing the emergence of a dominant power or coalition in the Eurasian "World Island" that could threaten American security. Alliances are the most effective and sustainable tool for this, offering a middle ground between costly direct containment and dangerous retreat-and-reentry.

War prevention. Defensive alliances deter aggression by aggregating military resources, making the costs of expansion unacceptably high for revisionist states. Historically, periods of extensive defensive alliances, like the 19th century and the Cold War, have been characterized by prolonged peace.

• NATO's expansion into Central and Eastern Europe has deterred Russian military adventures and suppressed regional tensions.
• U.S. alliances in Asia have channeled China's power into a "peaceful rise," preventing major regional conflict.
• U.S. backing of Israel and Gulf states has maintained a balance of power in the Middle East, deterring bids for regional supremacy.

Containment and balancing. Alliances deny large powers access to critical geography (e.g., CEE states blocking Russian expansion, the "first island chain" containing China, Gulf states hedging Iran). They also empower weaker states to actively counterbalance larger rivals, leveraging their natural hostility to create "built-in regulators" against hegemonic ambitions. This allows the U.S. to outsource a portion of global leadership costs and achieve economy of force across multiple peripheries.

6. Allies Provide Indispensable Military and Economic Benefits to the U.S.

Without alliances, the United States would lose a significant chunk of world military capabilities.

Military multiplier. Alliances significantly multiply American power, providing human and material resources across land, air, and sea. Collectively, the U.S. and its allies command approximately 67% of global military spending and over 7 million troops, vastly outstripping rivals like China, Russia, and Iran. This combined strength is increasingly vital as the U.S. military advantage narrows and sophisticated technologies proliferate.

Complementary capabilities. Allies offer crucial military complementarity, especially in territorial defense. While U.S. expeditionary operations have highlighted some allied shortcomings, frontline states are now investing in robust defensive capabilities, such as anti-access area denial (A2AD) systems. These strengthen deterrence, buy time for U.S. response, and allow the U.S. to focus its scarce resources on areas of comparative advantage like long-range air and sea assets.

Power projection and economic stability. Allies provide essential forward bases, extending the reach of U.S. forces and acting as "trip wires" that enhance deterrence and reassure allies. This forward presence improves responsiveness to crises, reduces transit times, and lowers the overall force required for interventions. Economically, alliances underpin the U.S.-led Bretton Woods system, ensuring open markets and the dollar's status as the global reserve currency. Allies hold a significant portion of U.S. debt, and their presence near critical maritime choke points (e.g., Malacca, Hormuz) secures global trade and energy flows, providing vital competitive advantages in both peace and wartime.

7. Strengthening Alliances Requires Prioritizing the "Rimland Imperative."

The importance of these states is not measured in their physical size, power, or wealth but in the real estate that they occupy.

Strategic choices. In an era of scarce resources and intensifying competition, the U.S. must make strategic choices, focusing on areas most relevant to its security. The "rimland imperative" dictates prioritizing alliances in the key productive zones of the Eurasian "World Island"—a narrow belt from the Baltic Sea to the Black Sea, through the Levant and Persian Gulf, to the Indian Ocean and littoral Asia to the Sea of Japan.

Disproportionate impact. The fate of these rimland states—whether they remain stable, free, and aligned with U.S. interests—will disproportionately shape the 21st century. Their geopolitical pluralism is crucial to preventing revisionist powers from consolidating enough resources to directly challenge the U.S. Unlike allies in less critical regions, rimland states occupy territories that rivals covet as prerequisites to global competition.

Stabilizing the rimlands. The central goal of U.S. strategy must be to stabilize these regions by fostering clusters of politically confident, economically advanced, well-armed states aligned with U.S. interests. This requires restoring American credibility, which has eroded due to rival probes and U.S. deprioritization of alliances. The U.S. must visibly strengthen its alliances, prioritizing those most in need of attention and reinforcing the pillars of extended deterrence.

8. Restoring U.S. Political Will is Paramount for Alliance Credibility.

The process of rebuilding credibility must therefore start with revaluing alliances in U.S. foreign policy.

Addressing doubts. The most critical challenge to U.S. alliances is the widespread perception among allies that the U.S. lacks the political will to honor its security commitments. This doubt is fueled by U.S. leaders' rhetoric, occasional prioritization of rivals, and concerns that new "probing" threats fall below the threshold for American action.

Revised reassurance. Rebuilding credibility requires a revised approach to reassurance, moving beyond generic Cold War-era affirmations. It must be tailored to the disparate threat perceptions and coping strategies of individual allies, especially the frontline states.

• Empowering resisters: Provide full political and military support to states with the strongest incentive and ability to resist (e.g., Poland, Japan, South Korea).
• Buttressing the weak: Work with resisters to bolster smaller, willing-but-less-capable regional states (e.g., Baltic states, Philippines, smaller Gulf states).
• Nudging fence-sitters: Use diplomacy to stiffen resistance among nominal allies leaning towards accommodation (e.g., Bulgaria, Oman, Thailand).

Intra-regional differentiation. The U.S. should favor stronger bilateral relationships and ad hoc security groupings built on shared risks over large, multilateral alliances that may be less effective for frontline defense. This approach acknowledges that some allies are more inclined to oppose regional revisionism and can serve as hubs to radiate influence to others. In some cases, this may mean prioritizing security cooperation over other policy objectives, such as democratic governance, to strengthen the frontier.

9. Empowering Allied Military Capabilities is Key to Deterring Probes.

Creating stronger local defense capabilities among frontier allies is therefore imperative.

Addressing free-riding. The renewed fear among frontline allies presents an opportunity to address the "free-riding" problem by encouraging greater investment in their own security. However, this rearming must be actively managed by the U.S. to be effective and avoid destabilizing outcomes.

Making allies "prickly and indigestible":

• Robust local defense: Allies must develop capabilities to deter and react to low-intensity probes and limited wars, forcing aggressors to escalate and increasing the likelihood of external support. This includes both a "wall" (e.g., missile defense, anti-air defenses) to deter attacks and an "insurgency" approach to make conquest costly and untenable.
• Limited offensive capabilities: Allies need assets like medium-range cruise missiles, long-range artillery, and precision-guided munitions to strike inside revisionist territories. This is crucial for operational effectiveness, countering rival anti-access area denial (A2AD) capabilities, and reassuring allies that they are not merely "speed bumps."

U.S. role in capability building:

• Targeted proliferation: Ease export controls and speed up sales of advanced weapons to frontier allies.
• Joint R&D: Collaborate on developing affordable, abundant, and expendable weapons tailored for local, low-intensity conflicts.
• Focus on territorial defense: Encourage allies to prioritize local defense skills and assets over out-of-area operations.
• Intelligence sharing: Provide allies with operational "vision" regarding revisionist vulnerabilities and doctrines.

This approach aims to steel the space adjacent to revisionist powers, transforming small, weaker states into resilient targets and ensuring that the U.S. can maintain its global strategic frontier.

Last updated: December 10, 2025