Within three broad categories—negotiation, military action, and persuading China to force its ally to give up its nuclear program—the choices have remained largely the same over the years, as North Korea has advanced from secretly piecing together one or two warheads to boasting a usable nuclear arsenal (perhaps 10-20 warheads with lots more fissile material on the way) and openly testing short, medium, and, soon, intercontinental-range missiles to deliver them. Twenty years ago, it made sense to insist, as Secretary of State Rex Tillerson recently did, that North Korea accept denuclearization—giving up its nuclear weapons and facilities—as the precondition to negotiations. But because it fails to acknowledge all that North Korea has achieved in the interim, this position makes no sense today.

The military options have been reviewed, again and again, with the same conclusion each time: None are attractive. Seoul, a city of 10 million, lies just 35 miles from the DMZ, in range of Pyongyang’s heavy artillery. Enough of its guns could fire off a single round to inflict huge casualties on America’s ally before its planes could shut them down. While the United States could take out the North Korean nuclear or missile-launch facilities it knows of, there may be many it does not know of. And now that North Korea has mobile missiles, and solid-fueled ones that can be launched quickly, the picture looks even worse.

Under such conditions, a preemptive strike would be folly. North Korea would retaliate against Japan, South Korea, or the 28,000 U.S. troops stationed there, forcing Washington to respond. As North Korea began to lose, a conventional war would escalate into nuclear catastrophe.

Then there is the third option, increasingly prominent in recent years, of insisting that China solve this problem. This is a false hope. Short of forcing North Korea’s collapse, China cannot make it give up the very weapons it views as its only buffer against Armageddon. And China, for reasons of its own national security, will not go that far. It fears the flood of refugees that would result from the collapse of North Korea, as well as the ensuing chaos of regime change and the dangers from uncontrolled access to its neighbor’s nuclear, chemical, and biological weapons. Its biggest fear, however, is a unified, U.S.-allied Korea, with American forces directly on its border. In that case, given Washington’s treaty ties with Japan on the east, and increasingly close relations with India to the west, China would feel itself encircled.

This is not to say that China is powerless. In temporarily shutting down coal imports from North Korea, which provide the Kim regime with desperately needed revenue, it has taken a promising step. It can and should inflict more pain by shutting down leaks in UN-imposed sanctions by Chinese companies and banks. But even the extreme step of shutting down oil exports to Pyongyang would not yield Trump’s desired outcome, where Beijing “solves” North Korea if only it saw the problem as America thinks it should.