Neutrality in the Indo-Pacific Faces a Critical Test

Great Power Competition Threatens Traditional Protections for Non-Aligned Nations

As tensions rise in the Indo-Pacific, many Asian countries face a difficult choice: align with major powers or attempt to remain neutral. This situation echoes a historical dilemma, but modern international law offers increasingly uncertain protections for those seeking to avoid entanglement in a large-scale conflict.

The Melian Legacy and Modern Challenges

The ancient siege of Melos, as recounted by Thucydides, illustrates the harsh realities of power politics. The Athenians famously asserted that “the strong do what they can and the weak suffer what they must.” Today, many nations in Asia may find themselves in a similar position, forced to navigate the demands of larger, competing powers. While international law, specifically Hague Conventions V and XIII of 1907, outlines norms for neutral-belligerent relationships, their applicability is contested, and many Asian countries aren’t parties to these agreements.

A recent study by the Council on Foreign Relations found that defense spending in the Indo-Pacific region has increased by 60% over the last decade, signaling a growing militarization and heightened risk of conflict. https://www.cfr.org/asia-pacific/defense-spending-indo-pacific

Indonesia’s Pragmatic Approach

Hitoshi Nasu, along with Arie Afransyah, has explored how Indonesia—a nation committed to a “free-active” foreign policy—might implement the law of neutrality. Their research identifies specific legal positions Indonesia could adopt, along with the associated risks. Many other Asian states are likely to pursue similar strategies, attempting to balance their national interests with the need to maintain peaceful relations with all parties.

Constraints on U.S. Military Operations

The ability of the U.S. military to project power in the Indo-Pacific relies on access to regional bases and logistical infrastructure in countries like Australia, Japan, the Philippines, and Singapore. However, these nations, if choosing neutrality, are bound by international law to prevent belligerents from using their territory. Hague Convention V prohibits hostile acts within neutral territory and restricts the movement of troops, munitions, and supplies.

These obligations, generally considered binding under customary international law, could significantly impede U.S. operations. The passage of military aircraft and projectiles could be denied, and logistical coordination, including repairs, could be hampered. Nasu notes that Iran recently reminded neighboring Gulf States of their obligations regarding airspace and military bases, highlighting the importance of these rules.

Bilateral Treaties and Potential Conflicts

The United States may attempt to leverage bilateral defense agreements, such as the Treaty of Mutual Cooperation and Security with Japan and the Mutual Defense Treaty with the Philippines. However, these agreements raise questions about whether allied partners can justify actions that violate their obligations under Hague Convention V. Nasu points out that Japan, during the Vietnam War, effectively denied a state of war to navigate these complexities.

Freedom of Navigation in Archipelagic Waters

U.S. forces depend on sea lanes for force projection and logistical support. However, the inviolability of neutral territory extends to maritime areas, including the territorial sea and archipelagic waters of nations like Indonesia and the Philippines. These countries control vast stretches of water—3,081,756 square kilometers for Indonesia and 589,739 square kilometers for the Philippines—that are strategically important for navigation.

Within these waters, U.S. warships are generally limited to innocent passage, navigating on the surface and adhering to specific rules. Neutral states can even suspend access to these waters for security reasons. Indonesia has designated sea lanes, while the Philippines recently enacted the Archipelagic Sea Lanes Act, further defining navigational rights.

Sustainment and the Risk of Blockade

Maintaining trade relationships with neutral Asian countries is vital for U.S. economic well-being and war-fighting capacity. However, belligerents may attempt to disrupt these trade links through blockades and ship searches. While Hague Conventions prohibit neutral states from supplying arms to belligerents, enforcement is often inconsistent, particularly among nations not party to the agreements. Indonesia, for example, has continued trading with Russia despite international sanctions.

The doctrine of qualified neutrality, which allows for arms supply to a belligerent, could further complicate matters. If the U.S. is perceived as the aggressor in a conflict, such as a potential intervention in Taiwan, neutral states aligned with China might invoke this doctrine to justify supporting China’s war efforts.

The Limits of Self-Defense

The United States may assert the right of self-defense to search neutral merchant ships suspected of carrying arms to an adversary. However, this right is constrained by the International Court of Justice’s narrow interpretation of “armed attack,” making it difficult to justify searches based on mere suspicion.

Navigating a Complex Future

Assured access to bases, uninterrupted navigation, and maintaining economic ties while disrupting the adversary’s trade are all critical for effective force projection in the Indo-Pacific. Asian nations will likely make pragmatic choices based on geopolitical and economic factors. Understanding their legal positions and potential responses is crucial for U.S. force posture and the future of international law governing neutrality.