Iran has announced it is sending its branch of the Red Crescent to try and break the naval blockade of Gaza. Am I the only one who thinks this is the match that could set off a regional war? Maybe not, with US troops still in the region providing a deterrent. But I have a hard time seeing how this doesn't end violently. There is no way that Israel lets an Iranian ship of all things through to Gaza. It's entirely possible that this ship, at least, won't include weaponry in its cargo (one of the reasons I'm reticent to support a wholesale lifting of an inspections regime targeting cargo entering Gaza is that I remember the Karine A). But the Israelis, quite understandably, aren't going to go on instinct on this one. Meanwhile, one has to think that an Iranian ship is significantly less likely to be boarded peacefully than any member of the "Free Gaza" flotilla, including the Mavi Marmara. And one gets the sense that the Iranians know this too, and are out looking for a provocation.
It's just not a good situation. And the intervention of Iran, it'll get worse before it gets better.