President Joe Biden's administration could soon have its foreign policy mettle tested like never before as China boosts its military aggression against Taiwan while proceeding with its naval expansion into the South China Sea.

If Biden thought he would get a breather from major national security challenges after the chaotic withdrawal from Afghanistan, he figured wrong. A direct confrontation between China and Taiwan would dwarf the significance of Afghanistan. And the repercussions could hit every American hard in the pocketbook. So it's worth paying attention.

In recent days, China has sent nuclear-capable bombers and other military attack aircraft — nearly 150 in all — into Taiwan's exclusion zone, stopping short of violating Taiwan's 12-mile territorial limit but making clear that Beijing respects no declared boundary with the staunchly anti-communist island that broke away from mainland rule after the Maoist revolution of the late 1940s.

Ever since President Richard Nixon withdrew recognition of Taiwan in favor of Beijing in 1972, Taiwan has watched its international influence steadily erode, even among previously stalwart anti-communist governments in Central America and the Arabian Peninsula. The fully developed island nation of 23.6 million has justifiable fears that it's about to be swallowed whole.

China has eclipsed the United States as Saudi Arabia's top trade partner. It became the main financial backer for the Panama Canal expansion. Heavy port developments at both ends of the Panama Canal give China an ability to put a chokehold on transit operations that affect 66% of sea cargo either originating or ending at U.S. ports.

China watched with interest as the United States and NATO presented no military response when Russia seized Crimea from Ukraine in 2014. Biden's and President Donald Trump's repeated statements of disinterest in fighting other nations' wars cannot have escaped President Xi Jinping's notice, especially following their turn-tail pullout from Afghanistan and ceding of control to the Taliban.

America's message to Beijing couldn't be clearer: Now's the time to apply maximum pressure on Taiwan to give up its independence and submit to Beijing's rule. The expansionist threat from China is so real that even communist Vietnam, which fought a bloody war against the United States, is now welcoming U.S. warships to deter Chinese expansionism.

Granted, Biden has arranged a deal to share top secret nuclear-powered submarine technology with Australia to counter Chinese incursions in the South China Sea. But that arrangement will take years to bring to fruition. The threat China poses to Taiwan is now.