Gargoyle, you make a good point to an extent.
To better clarify, it is stupid to use war as a tool to get what one wants. And all war is wasteful and destructive, regardless of whether or not it is justified, which is why it is only a valid choice as a last resort, when diplomacy has failed.
Hitler was stupid to wage war on Europe; Europe was not stupid to wage war back at him with help from it's allies.
Although the British Empire was not technically waging war on the US, we had a number of legitimate reasons to break away from it, and we attempted to so, it brought about war. We didn't make the war, we fought back and won.
The Civil War did not keep this country united; the Civil War was a strangulation by Lincoln of states which had legitimate grievances against the federal government of the US. These grievances built up over decades and had only a little to do with slavery and rather a lot to do with tariffs. The result was not the preservation of a union but an example of what happens when the British Empires and Hitlers of the world win, which unfortunately sometimes happens.
I suppose it boils down to your definition of 'diplomacy.' In modern times, such as in the example of the current war in Iraq, 'diplomacy' is defined by politicians as "We asked them to do it and they said no; therefore we have no choice but to wage war." To compare the US war against Iraq with the US war against the British Empire is a bit of a stretch in that light.
Phaedrus
