Russia is helping China close gap with US forces amid Taiwan tensions, warns longtime military leader

Sound alarms are blaring over an escalating partnership between Russia and China to subvert the U.S. Military amid rising hostility between the world powers.

Rear Adm. Mark Montgomery tells Fox News Digital that Moscow may be providing Beijing with technology to make its submarines harder for the U.S. Navy to detect, potentially eroding a key military advantage in the tensions over Taiwan.

"Russia is giving incredibly important technology to China. They're allegedly giving them submarine quieting technology," Montgomery, co-author of the new book "Axis of Aggressors," told Fox News Digital.

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Montgomery said Russian forces are providing the Chinese Communist Party (CCP) with submarine-quieting technology, an area where China has long sought to improve its capabilities. Such a transfer, he warned, could weaken a critical U.S. advantage in undersea warfare — a gap that has long favored American forces.

"Any weakening of our asymmetric advantage in undersea warfare is a big deal," he cautioned.

The Navy says its submarine force relies on technological superiority and stealth to maintain its undersea advantage, while China has continued to face weaknesses in submarine propulsion and quieting even as it rapidly modernizes its fleet.

Quieting technology reduces a submarines acoustic signature, making it harder to detect and track. Russian assistance in that area could help Beijing narrow the gap, complicating the U.S. Navys ability to find Chinese submarines in a potential future conflict over Taiwan's independence from the CCP.

The Chinese Embassy did not directly address whether Beijing has received Russian submarine-quieting technology when reached by Fox News Digital.

"Military cooperation between China and Russia consistently adheres to the principles of non-alliance, non-confrontation, and non-targeting of third parties, playing a significant role in safeguarding the sovereignty and security of both nations and maintaining international and regional peace and stability," the embassy said in a statement. "We hope that relevant parties will view China-Russia military cooperation objectively and rationally, and stop groundless speculation."

The embassy said Taiwan is Chinas internal affair and urged the U.S. to safeguard stability in the bilateral relationship and across the Taiwan Strait.

Montgomerys warning echoes concerns raised by Adm. Samuel Paparo, commander of U.S. Indo-Pacific Command, who told the Senate Armed Services Committee in April 2025 that China was receiving "potentially submarine quieting help" from Russia.

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Paparo said Chinas backing of Russias war effort — including machine tools and legacy chips — was part of a broader exchange in which Moscow was returning assistance in military areas where it holds particular strengths.

The exchange reflects a deepening relationship in which Russia and China are increasingly providing capabilities the other lacks, Montgomery said.

"This transactional relationship is putting the United States and its most important allies and partners at risk," he said.

Paparo sounded a similar warning in November 2024, saying he expected Russia to provide China submarine technology that could help close Americas undersea advantage. He de