While Barack Obama looks like a moderate guy in many respects, and his successful execution of Osama bin Laden is a recent example, there are also situations in which he turns out to be a largely uncontrollable threat for the democratic civilization.
He wants Israel to return to pre-1967 borders.
Between June 5 and June 10th, 1967 (the Six-Day War which was both pre-emptive and helpful for Israel), the yellow Israel on the map manage to win the Golan Heights (still controlled by Israel but the population is just 40,000; international deniers of reality consider it a part of Syria), Judea (South) and Samaria (North; in combination Judea and Samaria are known as the West Bank, currently under military control of Israel but administered by the moderate Fatah's Palestinian Authority), Gaza Strip (currently controlled by the Hamas terror group, but still somewhat unofficially supervised by Israel), and the Sinai Peninsula (peacefully returned to Egypt shortly after the 1967 war).
Just try to impartially ask the question: is the yellow region defensible? I find it totally silly. To return to pre-1967 borders means to probably return to pre-1949 borders - i.e. to eliminate Israel off the map - within another decade. It's crazy that someone may propose something of the sort while calling himself an ally of Israel. In this sense, the difference between Obama and Ahmadinejad may be just a few years. Make no doubts: the democratic consensus among the "Palestinians" is that the Jews should be pushed to the Mediter. sea. Obama clearly agrees.
As Bibi Netanyahu correctly said, Obama doesn't understand reality.
Obama's proposals will either quickly die, showing that Obama is just a loser and crazy kibitzer who is disconnected from reality and whose big words don't mean anything; or they will not quickly die and Obama will work to realize them. In that case, I would find it pretty natural for Israel to try to assassinate Obama and any other future U.S. president who will threaten Israel's existence in a similar way.
And that Israel's existence is clearly what is at stake is completely obvious. Golan Heights, currently controlled by Israel, would become mountains from which you can easily get to the Galilee - the adjacent part of Israel. Or shoot at them. It's crazy. This is something that the Czechs know a lot about. The loss of the Sudetenland - the mountains naturally bounding the Czech kingdom for centuries - has made the smaller Czech lands (the "Second Republic", as the castrated territory is known to us) indefensible and, indeed, Hitler took the rest of the Czech lands within half a year, too.
Now look at the yellow strip on the Western side of Judea. It's about 20 kilometers thick in the thinnest parts. Tel Aviv, the formal international capital of Israel, is somewhere in this thin strip. You gotta be kidding, right? If forces that are hostile to Israel are allowed to thrive in Judea and Samaria, and allowed to exchange "goods" with other hostile Muslim countries, Israel (or maybe I should call it just "rae") is going to be destroyed soon.
The situation is even crazier in the case of Jerusalem. This de facto capital of Israel is located in the Western "hole" in the West Bank - it separated Judea from Samaria; look at the map. It's almost completely surrounded by the "Palestine" and if you run 3 miles on the West side of Jerusalem, you will encircle it completely. The same easy Palestinian access exists in the case of the local airports etc., too. That makes a siege about 1,000 times easier than the Siege of Leningrad.
It's just crazy.
Now, would the small indefensible Israel be protected by the U.S. in the case of trouble? I don't think so. What's happening today is enough to predict how the U.S. led by someone like Obama would react to a "purification" of the region by some Muslim powers. When Obama came to power, America ceased to be an ally of Israel and it may be pretty correct to say that it became an enemy yesterday.
Obama's plans represent the most threatening plan by a top global politician for the existential interests of the Jewish people since the 1940s. Needless to say, Israel haters across Europe - not only Angela Merkel - have endorsed Obama's idiocy, too. But that's not unexpected; after all, Germany has been the birth place of some worse plans how to treat the Jews and Merkel is much less anti-Semitic than some of her most famous predecessors. But America used to be an Israel's ally. As socialism spreads over America, so do anti-Israeli policies.