President Trump this week has gone from saying the U.S. will respond to North Korean threats with “fire and fury like the world has never seen” to clarifying those words were perhaps not “tough enough,” and to spelling out Friday, in case there were doubts, that the U.S. military was “locked and loaded” to counter any threat.

The comments are likely to attract criticism, given that they raise already high tensions with North Korea, a nation that now possesses intercontinental ballistic missiles capable of reaching the U.S.; is said to possess a miniaturized nuclear device it can fit into that missile; and has threatened in recent days to strike near Guam, the U.S. territory in the Pacific that is home to U.S. military bases. But the remarks also raise questions about what sort of response the U.S. is considering in the event the North Korean leader decides to flex his military muscles.

Trump, in tweets this week, noted the U.S. nuclear arsenal “is now far stronger and more powerful than ever before,” adding he hoped “we will never have to use this power.” It is widely believed that the U.S., the only country in the world ever to use nuclear weapons, will only use such weapons in the event of a first strike against its interests. Members of his Cabinet, have been quick to repeat that old saw: that while the U.S. prefers diplomacy, all options are on the table.

Still, the president has sole authority to use nuclear weapons. Members of his Cabinet who disagree have the right to resign, but the military is obliged to carry out the order. As Bloomberg News points out: “It takes just two ‘votes’ to launch the missiles. So even if three two-officer ICBM crews refuse to carry out the order, it won’t stop the launch” of nuclear weapons. Even if Trump orders the use of nuclear weapons, it is probably not a good idea for his military to refuse the order. As Bruce Ackerman, a professor of law and political science at Yale University, told The Washington Post, the example of Latin American nations, many of which have modeled their constitutions on the U.S., shows that when militaries defy their presidents, the consequences  are usually “terrible.” In other words, Trump’s order to use nuclear weapons may be unpopular, but the long-term consequences of the military’s defiance of a civilian president’s order could be worse.

This argument, of course, is based on the idea that North Korea will order a first strike. This, too, is seen as highly unlikely because while Kim might be the object of punch lines in the West, he is practically God in his own country. His control of North Korea is seen as near total. Any potential rivals for power have been quickly dispensed with. His fortune is worth billions. He is 33 years old. There is virtually no reason for him to use nuclear weapons. Unlike the Soviet Union during the Cold War, he does not possess the nuclear arsenal to threaten the U.S. with mutually assured destruction. Any use of such weapons by Kim would almost certainly assure his destruction. North Korea maintains its nuclear and missile programs are strictly defensive in nature to counter what it calls provocations by the U.S. and South Korea. What is likely, however, is continued North Korean missile tests in the Sea of Japan and elsewhere to show its military and technical prowess, as well as occasional nuclear tests.

There is, of course, the possibility that Kim orders North Korea to strike near Guam as early as next week, as his military said in great detail that it could. If those missiles land in Guam’s waters, the U.S. response could be conventional (non-nuclear) in nature. The U.S. military has a large presence in South Korea (28,500 troops) and Japan (54,000), and could easily target North Korea’s command-and-control capability, its nuclear programs, and its missile launchers. The consequences of such a response are likely to be catastrophic not only on North Korea but its neighbors: Not only are there more than 70,000 U.S. troops within the reach of North Korea’s short- and medium-range missiles, nearly half of South Korea’s 50 million people live about 100 miles from the demilitarized zone (DMZ) that separates the two Koreas. The loss of life would be horrific.

Having said all of this, the U.S. is not on a military footing in the region. There is no direct threat to the U.S. at the moment. The U.S. is unlikely to have international diplomatic support for the kind of military action Trump appears to be suggesting. Nor is it clear Trump is doing anything other than sending a message to Kim—a leader who not long ago he described as a “smart cookie” whom he “would be honored” to meet—that the North Korean leader should rein in his threats. The same could be said about the U.S. president.