Let's imagine, and this is purely hypothetical, that President Bush has already decided that he will not leave office in January 2009 without a satisfactory resolution of the Iranian nuclear problem. Let's imagine that he has already determined that if he cannot obtain Iran's agreement to dismantle its nuclear weapons program voluntarily and verifiably, then he will order some form of military action to destroy as much of that program as possible before he leaves. Let's imagine that he has resolved not to end his two terms in office the way Bill Clinton ended his, by leaving every major international crisis -- from Iraq to Iran to North Korea to al-Qaeda -- for his successor.
I think Kagan has too much intellectual integrity to go re-writing history (unlike some other conservative pundits), so he must genuinely believe what he wrote here. I'm no foreign policy expert like Kagan, but I think we've pretty well established that Iraq was not a "crisis", and it's been the Bush administration's unwillingess to deal with North Korea that's resulted in the present situation. As for Al Qaeda...in hindsight it's obvious that more should have been done, but let's not forget that it was Republicans who currently support the war in Iraq who were ridiculing the Clinton administration for that strike on a supposed Sudanese chemical weapons factory. So, let's keep things in perspective okay?
As for the rest of his column....well, you'll have to read it to get the full flavor, but I can at least give you the gist of it. Kagan is essentially saying that the current diplomatic process we're going through with Iran is a necessary precursor to any military action, not necessarily a step backwards from such action, and that it's entirely possible that Bush still intends on military action but realizes he must endure this process to get to that point. Now you can take that in one of two ways. As an Iran war hawk you can tell yourself "Oh well then things aren't so bad. We're just doing this to show the world we tried, before we bomb the hell out of Iran for not cooperating anyway." Or as a opponent to war against Iran you can say "Well, we have to engage in the diplomatic process because it's the right thing to do, and if it fails, well then we'll have established our credibility and we'll have no choice anyway, so okay." So he's cleverly reassuring both sides? I'm not sure. Read for yourself and see what you think.