In an attempt to raise tensions and flex their military muscles at China's doorstep, the US and Canadian navies sailed two warships through the Taiwan Strait on Saturday.

The fact that this is their second provocative "joint mission" since June shows Washington is hell-bent on playing the Taiwan card and mounting strategic pressure on Beijing. But Washington should be cautioned that there is a limit to Beijing's patience.

The US Navy's 7th Fleet said the guided-missile destroyer USS Ralph Johnson and Canada's HMCS Ottawa conducted the "routine" transit "through waters where high-seas freedoms of navigation and overflight apply in accordance with international law". But "freedom of navigation" is a pretext the US has always used to challenge China's territorial claims.

Such reckless moves lay bare the US' insincerity when it says it wants to normalize Sino-US relations and resume normal communication between the two militaries. Since the Shangri-La Dialogue in Singapore in June, the US side has been complaining about the lack of contacts at the senior level between the two militaries, even highlighting its potential risks.

The reality is that the frequent sailing of US warships through the Taiwan Strait and close to disputed waters in the South China Sea has eroded the strategic mutual trust between the two countries, increasing the risk of strategic miscalculations and misjudgments.

The more frequently US warships, along with those of its allies, sail through China's waters, the higher the possibility of a head-on conflict between the two militaries. That US high-level military officers have, in recent months, urged China to resume high-level military contacts suggests Washington, too, does not want to see such a worst-case scenario.

Last month, Vice-Chief of the Joint Staff Department of the Central Military Commission Xu Qiling held a meeting with senior US military officers in Fiji. It was the first person-to-person contact between the two militaries this year and eased, to a certain extent, the concerns over the lack of contact between the two militaries.

Yet the latest US move shows Washington is not sincere about meeting Beijing half way and building on last month's momentum to normalize high-level military contacts.

Washington should know its warships will not daunt the People's Liberation Army. Instead, the US' muscle-flexing will only prompt China to expedite the modernization of the PLA and build it into a world-class military.

The PLA has intensified patrols and held military exercises to enhance its combat readiness, so that it can promptly deal with new challenges and risks. Hence, Washington should stop provoking Beijing by sailing its warships through China's waters, including the Taiwan Strait, and disturbing peace in the region.