The do not attack argument fails on at least 3 points:
1. Iran is not Iraq. Therefore, you can”t point to the failure in Iraq as evidence for why there should be no attack against Iran. First, there was never any credible evidence that Iraq posed a threat to the West. Iran, on the other hand, is bragging of its efforts to develop a “peaceful” nuclear capability. The trouble is, Iran refuses to limit its uranium enrichment to peaceful levels. So, Iran definitely constitutes a threat whereas Iraq did not. Second, the attack against Iran would be an air war and not an occupation. It would be designed to set back Iran”s nuclear program and could be repeated whenever the program progressed to the point where the threat reappeared. No dead US soldiers, no allied occupation, no occupation. Iran is not Iraq.
2. There is good reason to fear that Iran”s leadership would not be deterred by the concept of MAD – mutually assured destruction – which deterred the Soviet leadership from using nukes all through the cold war years. These religious fanatics might actually like the prospect of (a) bringing on Judgment Day via nuclear Armageddon, or (b) just reshuffling the deck through a nuclear exchange with the West in the hope that this time it gets dealt a better geopolitically strategic hand (especially when there”s always prospect (a) to fall back on).
3. Appeasement doesn’t prevent war, it just makes it worse when it happens. Weren’t we supposed to have learned this already from WW2? The best time to stop Hitler would have been when he reoccupied the Rhineland in violation of the peace treaty ending WW1. Yes it would have meant war but it would have been fought entirely in Germany, it would have been of short duration, and its outcome would have certain victory for the West. How many millions of lives would have been saved? How much misery prevented?