To posit that war, as a tactic, doesn't "work" anymore doesn't mean to suggest that war has worked in the past. It has never been a positive proposition, period.
However, I concede that engaging in wars to stop the likes of Napoleon and Hitler or, in our most famous case, to gain independence from Britain, have been apparently necessary. That "success" in those wars came at such a cost cannot be understated. Also, history has a way of distorting itself: The United States required a war to rid itself of British rule, while Canada gained its freedom peacefully. Which country was right? Did we really need war in that case?
We can't know because our cause succeeded, and our history supports our mythology.
However, our most recent wars, since Korea, have been dismal failures. Korea remains divided some sixty years later. Vietnam was, historically, one of the most violent and expensive wars in our history, and yet, what did it accomplish besides killing millions? Nothing. Our Iraq and Afghanistan adventures have contributed mightily to our long-term debt and have lowered our standing in the world. There is little evidence to suggest good outcomes in either theater. The Iraq War strengthened the Shia, increasing Iranian influence in the region, and Afghanistan has again proved itself the destroyer of empires while our efforts there succeeded mainly in heightening militancy in neighboring Pakistan. When we leave -- and leave we will and soon -- we'll leave an Afghanistan barely better off than before, if at all. Well done, America!
In limited military actions, we have had some successes. Our belated efforts in Bosnia and Kosovo halted ethnic cleansing and led to stability that holds to this day. That model may have helped end the bloodshed in Libya, though we don't know what the outcome will inevitably be. I can't fault the effort, however. And I'd be remiss if I didn't speak to the apparent success of the Persian Gulf War. What tempers me there is that, years later, Saddam was up to his usual tricks. Also, diplomacy was not seriously tried. Could Kuwait have been freed without violence? It's now unknowable.
What has to be acknowledged is the overwhelming arc of history and how it speaks loudly to the obsolescence of war. We needed to help Libya because Qaddafi engaged in an obsolete tactic, just as we may need to intervene in Syria because al-Assad is doing the same. I can reject war and violence as a tactic while conceding that in its waning days as an option there are times when military action is still inevitable.
Obviously, the saber-rattling concerning Iran is what brings this discussion to mind today. The situation there is tailor-made for a diplomatic solution driven by effective sanctions, sanctions that are clearly biting. If we attack Iran, we strengthen the mullahs. If we don't, we undermine them. It's as clear a case for not resorting to war.
We will continue perhaps for a century or so to reach for the gun rather than the telephone, even though stable relations among the remaining great powers -- the U.S., Europe, China, Russia, and Japan -- will steadily reduce the need for large militaries and massive defense spending. It will also reduce the number of interventions and police actions that annoyingly continue to spring up.
Someday, Russia, China, and the U.S. will run out of client states whose dictatorships we foolishly support, and when we do, proxy struggles will come to an end. That's when peace can finally start to reign and the higher calling -- to end disease, hunger, and poverty in the blighted areas of the globe -- will at last be heard.
Until that time, governments and political parties need to come to accept the pleasant notion that war is and should be a vanishing option. It simply doesn't work anymore.
It's impossible not to end on a frightening, dystopian note: War can only become obsolete if we solve global warming, prevent large-scale famine, and avoid conflicts over shrinking resources such as oil, metals, and water. If we can't deal with that, human history may seal itself in a final epic struggle that historians might not be around to record.
What a dismal outcome that would be. Let mankind know that moment and realize that only by working together do we survive these monumental challenges.