Donald Trump is running out of patience with North Korea. Using heated language unusual for a U.S. president, Trump recently warned that if Pyongyang threatens to attack the United States again, the U.S. will respond with "fire and fury like the world has never seen." Whatever action Trump decides to take, he must recognize that the stakes — not just for the Korean Peninsula, but also for America's relationship with China — could not be higher.

North Korea's two latest intercontinental ballistic missile tests, carried out last month, suggest that the country now has the capability to hit the continental U.S. The U.S. Defense Intelligence Agency has concluded that North Korea may well have already developed a miniaturized nuclear warhead that could be delivered on such a missile. Experts from Johns Hopkins University anticipate a sixth nuclear test at any moment.

The United Nations Security Council has now unanimously passed the harshest sanctions yet against North Korea, in the hope of pressuring the small country to renounce its nuclear-weapons program. The resolution bans North Korean exports of coal, iron, iron ore, lead, lead ore, and seafood products, which together account for one third of the country's already meager annual export revenue of $3 billion. It also prohibits countries from issuing new permits to North Korean workers abroad, whose wages, it is suspected, help fund nuclear and missile programs.