China’s Military Build-up Has Created ‘Pressure’ in Southeast Asia, Australian Defense Chief Says

Australia’s defense minister warned that China’s rapid military expansion is increasing pressure across Southeast Asia. Richard Marles said China has not explained why it is building up so extensively. That uncertainty, combined with Beijing’s growing assertiveness, is making regional governments more concerned about security and stability.

The warning comes amid several developments. Australia protested China’s test of a nuclear-capable ballistic missile in the South Pacific. China has also increased the frequency and intensity of incursions into areas of the South China Sea claimed by the Philippines. These actions have produced increasingly dangerous confrontations between Chinese and Philippine forces.

Marles said Australia and like-minded partners should deepen cooperation. He argued that countries need a shared understanding of the “rules of the road.” Australia is a middle power, he said, so those rules help it act with greater influence. The warning points toward closer coordination among regional partners as tensions continue.

The comparison places China’s military expansion at an extraordinary historical level. Richard Marles described it as “the biggest conventional military build-up” since World War II. That means he was comparing China’s current expansion with major conventional military expansions over the decades after 1945.

The article does not provide a precise budget, troop total, weapons count, or percentage increase. Instead, it emphasizes the scale through Marles’s historical comparison. He also said China had not explained why it was undertaking such a large build-up. The lack of an explanation adds to the pressure felt by neighboring countries.

The comparison matters because the expansion is occurring alongside more assertive Chinese activity. Australia protested a nuclear-capable ballistic missile test, while the Philippines has faced more frequent and intense confrontations in the South China Sea. Together, these developments are pushing regional states toward stronger cooperation and defense planning.

ASEAN is the regional grouping at the center of the meetings described in the article. The ADMM is its defense ministers’ meeting. ADMM-Plus expands that setting by bringing together defense ministers from ASEAN’s 11 member states and eight dialogue partners. Those partners are Australia, China, India, Japan, New Zealand, Russia, South Korea, and the United States.

The meetings provide a place for governments to discuss defense concerns and practical cooperation. At the Cebu gathering, the United States proposed stronger maritime awareness, better interoperability, and more cooperation among navies. These efforts can help participating countries understand activity at sea and work together more effectively.

The forum also shows how diplomacy affects defense cooperation. China accused the Philippines of obstructing its attendance, and China’s defense minister did not attend. Beijing instead sent its defense attaché, the lowest-ranking Chinese representative at an ADMM-Plus meeting since 2010. The dispute weakened the cooperative atmosphere.

China and the Philippines are confronting each other because both sides are involved in disputes over contested parts of the South China Sea. The article highlights Scarborough Shoal and Second Thomas Shoal in the Spratly Islands. These disputes have become a major source of tension between Beijing and Manila.

China has increased the frequency and intensity of its incursions into areas claimed by the Philippines. Those activities have led to increasingly dangerous confrontations. In July, a Philippine marine was injured during a melee with Chinese sailors at Second Thomas Shoal. The incident shows how quickly maritime disputes can become physical and dangerous.

The conflict is also affecting diplomacy. The poor state of China-Philippines relations overshadowed the ADMM and related meetings. China accused Philippine politicians of obstructing its participation, while the Philippine defense secretary said China had been given an opportunity to present its position. Continued encounters are likely to keep regional security discussions tense.

More frequent maritime confrontations raise the risk of accidents, injuries, and wider escalation. The article describes increasingly dangerous encounters between China and the Philippines, including a July melee that injured a Philippine marine. Such incidents also worsen political relations and make future encounters harder to manage.

Diplomatic disputes can damage the meetings designed to reduce those risks. China accused the Philippines of blocking its participation in ADMM-Plus, and China’s defense minister stayed away. Beijing sent its defense attaché instead. The meeting still had Chinese representation, but at the lowest level since the forum began in 2010. That reduced the opportunity for direct defense-minister engagement.

The broader effect is greater pressure on regional security cooperation. The United States proposed stronger maritime awareness, naval interoperability, and practical cooperation. Australia’s Marles also urged partners to work more closely. These efforts may become more important as confrontations and diplomatic disputes continue.

The “Squad” is an informal defense and security group made up of Australia, Japan, the United States, and the Philippines. Its members met on the sidelines of the ASEAN defense meetings and committed to greater defense policy coordination. It was their sixth meeting in four years, showing sustained attention to shared security concerns.

Three practical tools can strengthen their cooperation. Maritime domain awareness helps countries understand activity at sea. Interoperability helps their forces work together. Coordination aligns defense policies and improves their ability to plan joint responses. The United States specifically identified these areas, along with cooperation among navies.

The group is responding to pressure felt across the region. Marles said all four countries understood the challenges and pressures facing Southeast Asia. He urged them to deepen cooperation with friends and neighbors. Continued coordination could support collective security as China’s military build-up and maritime assertiveness remain major concerns.

A rules-based international order means countries rely on shared principles, agreements, and accepted conduct rather than only military power. These rules help establish expectations for how states behave. They can also give countries a common basis for cooperation and for challenging conduct they consider destabilizing.

Marles linked this idea directly to Australia’s position. He said a middle power like Australia gains agency from “the rules,” because rules shape how regional security works. Australia therefore has more influence when partners share an understanding of the rules of the road. Cooperation can make those rules more meaningful in practice.

The issue is especially important as China’s military build-up and maritime assertiveness create pressure in Southeast Asia. Australia protested China’s ballistic missile test and is coordinating with partners, including the Squad. Marles argued that allies and partners should work more closely to preserve a favorable balance and collective security.