The following is from an editorial in the Chicago Tribune:
There is a vigorous war of words going on between North Korea on one side and the United States and South Korea on the other. Anyone who likes trash talk should be amply entertained. But we shouldn't ignore the actual risk all this entails.
North Korea's government threatened to hit the U.S. with nuclear armed missiles, and the U.S. had strategic bombers fly practice runs in South Korea.
Pyongyang staged a mass rally with citizens urging "Death to the U.S. Imperialists."
South Korea fired back that it would "respond strongly" to "any provocation."
On Sunday, the Obama administration sent F-22 stealth fighters to South Korea, to go with naval deployments in the area.
All this would be more worrisome if the two sides had not been through this noisy ritual so many times.
North Korea has good reason not to back up its threats with action. It does have nuclear devices, though it probably hasn't figured out how to shrink them to fit on a rocket.
There is also the stark fact, well-known to the North Koreans, that the use of nukes would mean the immediate extinction of the regime.
The Obama administration has responded appropriately, with firm statements and shows of military force designed to underscore its determination.
No one in Washington has forgotten that the North's 1950 invasion of the South came after the U.S. secretary of state delineated the American "defensive perimeter" in such a way as to exclude South Korea.
The U.S. has to be clear, calm and immovable in its commitments.
Firmness has kept the peace before, and with a little luck it will again.