Quick: How many countries was America at war with last year?
If you accept the old fashioned notion that to drop a bomb on a country is to be at war with it, the answer is, oh, half a dozen or so. As Peter W. Singer points out in a New York Times opinion piece, since the beginning of last year we've conducted drone strikes in six countries: Afghanistan, Pakistan, Iraq, Yemen, Somalia... and... and... well, Singer doesn't list them, so I'm not sure what the sixth one is.
But that's kind of the point. We've moved into a time when the citizens of what is supposed to be a democracy have become removed from decisions about waging war. Not only does America not bother to actually declare war any more (something that hasn't happened since World War II); President Obama doesn't even bother to give us a heads up. You just wake up and read that we dropped some ordnance on Somalia and, if you're keeping a list, add Somalia to the list.
Singer's speciality is the roboticization of war--he wrote a book called "Wired for War"--and he attributes this new casualness of war to its risklessness: Since drone strikes don't put our sons and daughters in harm's way, Americans don't complain about them.
It's a good point, but I think it's only half the story. There's something else that makes presidents tempted to initiate hostilities promiscuously, and to me it's at least as alarming as the alluring roboticization of war.