I'd argue that Peacekeeping tours meet the Realpolitik demands that I mentioned above. Why do you think Canada contributed 3 battalions to the Balkans at one point (CANBAT 1, CANBAT 2, CANLOGBAT) and yet in terms of real gestures ignored places like Rwanda, the Congo, and Cambodia. "Peacekeeping" is just an easy "sell" to the Canadian public (for many of the reasons that PBI mentions) because it makes us think we have the moral highground.
"We're refuse to debase politics to a Machiavellian level, we're Canadians and we're better then that. As such, our military force will be used to Peacekeep."
While it may sound awefully enlightening, I think this is a "feel-good" smokescreen. Just look at the record of Peacekeeping and Interventions and come to your own conclusions.
- Korea (Ok, before the time of peacekeeping, but along the same mentality of intervention in other peoples conflicts.): Second challenge (After Greece and the Marshall Plan) to the policy of Containment that the US adopted.
- Suez (The original Peacekeeping Mission): Did we really care about who won in the Middle East inferno - or were we concerned because the Soviet Union threatened to turn Paris and London into parking lots over the issue.
- Golan Heights (yep, we're still there too): Did we really care about who won in the Middle East inferno - or were we concerned because the Soviet Union threatened to turn Haifa and Tel Aviv into parking lots if the IDF marched into Damascus and Cairo?
- Cyprus: As I said before, staving off a war between the two allies who made up NATO's "Southern Front".
- The Balkans: As I said before, a stable and secure Europe.
- Somalia: A little more difficult to define, I think this one was executed with in a manner of "chasing" a new outlook on security with the post-Cold War "peace dividend" on the mind. We got away from the two principles I mentioned earlier; as a result, the mission was an unmitigated disaster (both for Canada and for the US/UN forces in general).
- East Timor: Were we really concerned for the Timorese? Or were we concerned about the stability of a Muslim state of about 200,000,000 people that was right next door to our Allies in the Southern Pacific, Australia (yes, they have their own interests).
- Afghanistan (Op Athena): That's a no-brainer.
Of course, you're going to find outliers (Ethiopia, Haiti, Somalia as mentioned above) which may not have so obvious of a purpose, but these missions are usually the ones that are launched to satisfy intense public outcry, and these are the missions that are folded up as soon as the media (and the public) loses interest and finds something else to watch.
Peacekeeping, then, is merely an "extention of politics by other means" (Didn't someone say that already?). As such, the politics of Peacekeeping are informed not so much by idealism and notions of "the value of human life" and "a belief that civilization was worth it" - although elements will exist; look at Llyod Axworthy (and his failure). Rather, these commitments are determined by self-serving, calculated decisions - and, for the sake of you and me - it's how they should be.