Under such conditions, history's wars usually start when some opportunistic -- but often relatively weaker -- power does something unwise on the gamble that the perceived benefits outweigh the risks. That belligerence is only prevented when more powerful countries collectively make it clear to the aggressor that it would be suicidal to start a war that would end in the aggressor's sure defeat.What is scary in these unstable times is that a powerful United States either thinks that it is weak or believes that its past oversight of the postwar order was either wrong or too costly -- or that after Afghanistan, Iraq and Libya, America is no longer a force for positive change.
A large war is looming, one that will be far more costly than the preventative vigilance that might have stopped it.