What’s going on in Gaza now is pretty easy to understand if you think a little bit about the way military trends have been going in the past century-but you also have to be willing to take a cold look at how wars work these days, when there’s no such thing as those “purely military” wars you WW II freaks dream about. (There never really was, but that’s another story.)

The Israelis attacked now because of two non-military cycles: the news cycle and the presidential cycle. This was like a war by an astrologer: the stars had to be in exactly the right position before the Apaches could start blasting and the Merkavas could roll.

The most important cycle of all is the news cycle. This war happened during international media dead week, between Christmas and New Year. Ordinary people are drunk or hungover or snowed in, and the people who matter, the media players, are off in Cancun and Phuket, soaking up rum and sun with their blackberries turned off. They’re not going to bum out their call girls watching the news from Gaza.

And the Israelis wanted a time when everybody was distracted for a simple reason: asymmetrical war isn’t pretty. That’s the same reason they won’t let camera crews into Gaza. To do this kind of war, you have to kill a lot of civilians, because the whole civilian/military distinction doesn’t really apply. If your neighbor is a mid-ranking officer in the military wing of Hamas, the best way to kill him is while he sleeps, before he can arm himself, deploy his men and maybe inflict casualties. Thanks to years of excellent intelligence on Gaza, the Israelis know exactly who’s where at pretty much any minute of any day. And they have attack helicopters hovering over it non-stop, ready to send a Hellfire missile down to take out anybody who might help organize a counterattack.

But Gaza is the most crowded slum in the world, so when you send that missile into his tenement apartment at 4 am, it’s going to kill him, but it’s also going to kill his wife, their kids (and Gaza has a huge birthrate) and half the block. That makes cold military sense but it doesn’t look good on the news.

Of course you could send troops in, the idea being they’re cleaner than missiles, but sending troops into a highrise slum full of people who hate your guts is not such a good idea if you’re worried about casualties. And like I’ve said before, the IDF has one big weakness: they don’t like to take casualties.

So naturally they did what they could to decapitate Hamas from the air first, then with artillery. Besides, the idea that raids by infantry are less bloody than air strikes is pretty dicey anyway. Troops get nervous, they start shooting, pretty soon the collateral damage bill is just as big as it would be with an air strike, only this way the raiding party suffers casualties too.

So it made perfect sense for the Israelis to step up their longterm policy of zapping Hamas cadres from the air, and to do it right now, while nobody’s watching TV.

The other cycle is more of a gamble: the presidential cycle. I can’t believe nobody’s saying the obvious here: the Israelis want to do this now, once and for all, while Bush is still in office. They know that Bush will let them do whatever they want. Bush and Cheney are literally more extreme than about half of the Israeli electorate. They’ve never objected to anything Israel wants to do except when the Israelis wanted to talk to the Syrians. As long as it involves blowing stuff up, Bush is guaranteed to be on their side.

So the planets aligned perfectly for Israel, not so much Age of Aquarius way as Zero Hour, last chance to blow up Gaza before Obama comes in.

Will Obama be more hardnosed with the Israelis? I doubt it. Why would he? You’re not supposed to say out loud that there’s a big rich Israeli lobby, but everybody knows there is. And more to the point, what’s their counterweight? Who cares about the Palestinians, even in the Arab world, never mind DC? So there’s a big net gain to any US politician who backs Israel and no reason at all to back their opponents.

So I don’t see why the Israelis are so worried about Obama. Still, a military planner’s job is to be paranoid and the Israeli staff has decided that since Bush is a sure thing and the new guy is an unknown quantity, why not do it now?

I’ll tell you something else: Obama’s people are cheering the IDF too, for the timing at least. “Dear IDF, Thank you for doing this while Bush is still around to take the heat! Signed, Barack.” That’s exactly what Obama meant when somebody asked him about Gaza and he said, “Hey, we only have one president at a time!”

That tells you something else about this operation: it’s likely to end before January 20, 2009. Obama doesn’t want his big inauguration party bummed out with pictures of dead Arab kids, so the IDF has this thing planned to end sometime in early January.

Of course planning is one thing, execution is another. The IDF planned for a quick clean fight against Hezbollah in 2006, but that’s not the way it worked out.

This time the IDF will succeed, at least in the short term, and the campaign will go according to plan. That’s my guess anyway. What we have here is Hamas getting a very hard lesson in why it’s dangerous to pretend you’re Hezbollah when you’re not.

Hezbollah fought so well last time around that everybody started getting uppity, and the Israelis didn’t like it at all. They weren’t getting respect. They couldn’t destroy Hezbollah, though; the Hezzies are too smart, too big, too well integrated with the locals in Lebanon. Hezbollah has all kinds of advantages that Hamas doesn’t have, like great strategic depth, pockets of Shia support all through Lebanon, far from the IDF’s reach (unless they tried another fullscale invasion of Lebanon, a real bad idea).

So for more than two years now Israel has had to put up with Hezbollah sitting just over its northern border with a smug little grin on its hairy face, strutting on the rep it made back in 2006-and there’s not much the IDF can do about it.