deterrence

For decades, this ambiguity has kept China guessing - a form of deterrence - while leaving room for economic ties to flourish.

The U.S. poured billions of dollars into the Vietnam War but underinvested in defense “in ways that significantly weakened U.S. deterrence and jeopardized U.S. national security in the midst of Soviet expansion,” Mr. Jones writes.

But the Pentagon simultaneously said Spain's contingent was playing "a fundamental and essential role for the defence of Europe and policies of deterrence", Spanish Defence Minister Margarita Robles said.

Messrs. Rogers and Wicker are giving the President sound counsel that this is no time to go wobbly on deterrence in Europe.

The United States has a sophisticated testing system that doesn’t require setting off explosions, and when it comes to deterrence, nobody in the world assumes that America’s arsenal is full of duds.