Robert Fisk writes about the role played by Indian peacekeepers in Lebanon. The essay is primarily about the relevance of the United Nations: he poses the question that, since Security Council Resolution 1559 is forcing Syria to withdraw from Lebanon, should the UN have been allowed to use its clout to make Saddam step down, instead of allowing the US to do so and make a right royal mess of it? My take is that, irrespective of whether you are for it or against it, the US military action did send shivers down the spines of countries like Syria and forced them to comply. I doubt whether 1559 would have had the same effect absent the American action in Iraq.
Having said that, the fact that Chirac threw his weight behind the resolution (Franco-Syrian relations go back a long way) could also have played a part.