Senator Tom Cotton (R-Ark.) isn't mincing words about China's military ambitions. The Arkansas Republican is warning that Beijing's rapid peacetime military expansion is increasingly aimed at isolating the United States from its Asian allies and even threatening American territory.

Beijing's Three-Decade Strategy to Keep America Out

"Communist China is engaging in one of the biggest military peacetime buildups in history with the clear goal of threatening American interests," Cotton wrote Tuesday on X. "Let me be clear: we will not allow a Communist dictator to threaten our friends in East Asia."

In a video accompanying his post, Cotton explained that China has spent the past three decades building a navy, air force, space systems, and what he called "novel weapons" specifically designed to prevent the United States from staging the kind of slow, deliberate military buildup it used against Iraq in 1990–91. The goal, he argues, is to make American intervention impossible before it even begins.

Those forces are intended to "push us away from treaty partners like South Korea and Japan… and push us away from Taiwan… and even threaten our own territory in places like Guam," Cotton said. He's calling for Washington to increase defense spending and send an unmistakable message that China cannot use military force to coerce U.S. allies.

Japan-China Tensions Heat Up Over Taiwan Comments

Cotton's warning comes as tensions between Japan and China have sharply escalated following remarks by Japan's new Prime Minister, Sanae Takaichi, suggesting Japan would defend Taiwan if China invaded. According to a Reuters report on Tuesday, Beijing responded by filing a letter with the United Nations accusing the Japanese Prime Minister of "a grave violation of international law."

It's a diplomatic row that underscores just how sensitive the Taiwan question has become, and how quickly rhetoric can turn into formal diplomatic complaints.

U.S. Allies Echo the Warning

Cotton isn't alone in raising the alarm. According to an Associated Press report from March, U.S. officials and allies have voiced similar concerns as China's official defense budget grows faster than its overall economy, funding a rapidly expanding blue-water navy and expanding missile arsenal.

Australia's defence minister called China's expansion "the biggest military build-up in the world today" earlier this month, warning it threatens critical sea lanes essential for Australian trade, according to a separate Reuters report. Meanwhile, U.S. intelligence believes a massive underground complex under construction in western Beijing is designed as a hardened wartime command center, the Financial Times reported in January.

Guam Gets Reinforced as Pentagon Speeds Up Procurement

Cotton connected these trends to the ongoing U.S. military buildup on Guam, where Washington is relocating Marines from Japan and pouring billions into new facilities and missile defenses. He also praised Defense Secretary Pete Hegseth's recent efforts to overhaul the Pentagon's acquisition system, which Hegseth has centered around the concept of "speed to capability." Cotton argues faster procurement is essential if the U.S. hopes to keep pace with Beijing's military expansion.

The message is clear: China's building a military specifically designed to keep America out, and Washington needs to move faster to counter it.