Pyongyang’s latest and most powerful missile test demonstrates that China has not delivered on North Korea, as Beijing apparently promised U.S. President Donald Trump it would. Instead, it continues to deliver for North Korea, ignoring or undermining the very sanctions it voted for in the U.N. Security Council.

While some Chinese banks have cut ties with North Korean entities, plenty of illicit channels of trade and investment are allowed to provide ongoing life support to the regime. More important, Beijing continues to make clear to Washington, Pyongyang, and the world what its own geostrategic priorities are.

China is perfectly content to live with a nuclear-armed, missile-wielding, weapons-proliferating, terrorism-sponsoring, population-oppressing neighbor with a cultish Communist government. The alternative, from Beijing’s stated perspective, is regime collapse and a reunification of the Korean Peninsula under a democratic government favorable toward or at least not hostile to the West.

The Kim Jong Un regime therefore has a security guarantee from its powerful supporter -- no matter how outrageously it acts toward its own people, its neighbors, or international norms, the survival of the North Korean regime is China’s paramount interest.

For decades, the Chinese commitment to North Korea has worked almost perfectly for both systems. It has enabled Pyongyang to pursue its nuclear weapons and ballistic missiles programs, as well as committing acts of aggression against its neighbors and humanitarian crimes against its own people, all virtually unimpeded despite international condemnation.

The close “lips and teeth” relationship may still be more apt than thought by Western observers. Beijing provided the lip service that afforded Pyongyang diplomatic cover and economic sustenance while North Korea grew sharp nuclear teeth.

Serendipitously, the Beijing-Pyongyang understanding has produced a diplomatic and strategic windfall for the People’s Republic of China. It has parlayed its recognized leverage over North Korea into actual leverage over the West, winning it the key position at the world’s bargaining tables and plaudits as a supposedly responsible, and respectable, member of the international community.

It also grants invaluable immunity to Beijing regarding its own violations of international law and norms on trade, currency, intellectual property, human rights, Taiwan, and maritime and aviation security. Whenever the West is inclined to call China’s hand for its hostile behavior in those areas, our hand is stayed because “we need China on North Korea.”

We still do need China on North Korea, but Washington needs to up its game to get that critical cooperation -- or to do what President Trump has often promised the United States would do, and solve the problem ourselves. There is still ample space for diplomatic and economic actions to work before the last resort of military action is employed, but those actions must now be directed at China itself.

There is a range of China issues that require fresh American thinking and more forward-leaning approaches but on which Washington has chosen to exercise strategic patience. It is time for some of the Trump administration’s advertised strategic impatience. The North Korean canister has been kicked down the road for so long that, as Secretary Tillerson and U.S. ambassador to the United Nations Nikki Haley have both said, there is no more road.

The administration could start by picking up the Taiwan thread Trump pulled on when he accepted a telephone call from Taiwanese President Tsai Ing-wen. In doing so, the president warned Beijing that he does not regard as sacrosanct the one-China policy (separate governments to be united, if at all, only by consent of the Taiwanese people), let alone care for Beijing’s distorted one-China “principle” that Taiwan belongs to China, period.

There are myriad ways the administration can move forward to upgrade and deepen America’s ties with Taiwan -- an essential security partner in the South China Sea and the region -- diplomatically, economically, and militarily. More frequent interactions, and at higher official levels, in both Taiwan and the United States are essential to enhancing security cooperation in a region made increasingly threatening by the dangerous duo of Beijing and Pyongyang. The U.S. Congress is addressing some of these issues and the administration should be a willing partner.

Similarly, in the South China Sea the administration should resume and accelerate its invigorated Freedom of Navigation Operations that laudably replaced the previous tepid and counter-productive innocent passages. Given the mounting threats from North Korea, the “contingency” that Secretary Tillerson mentioned in his confirmation hearing looms closer. If it is not already doing so, the administration should revisit his suggestion that the U.S. Navy actively prepare to undertake operations blocking Chinese access to its illegal, militarized manmade islands.

Trump should make it clear to Chinese President Xi Jinping that, despite the warm personal chemistry that has developed since their Mar a Lago get-together and in Beijing, we hold his government’s policies responsible for allowing the situation to come to this.