Many American supporters of Israel who voted for Barack Obama now suspect they may have been victims of a bait and switch. Jewish Americans voted overwhelmingly for Mr. Obama over John McCain in part because the Obama campaign went to great lengths to assure these voters that a President Obama would be supportive of Israel. This despite his friendships with rabidly anti-Israel characters like Rev. Jeremiah Wright and historian Rashid Khalidi.
At the suggestion of Mr. Obama's Jewish supporters -- including me -- the candidate visited the beleaguered town of Sderot, which had borne the brunt of thousands of rocket attacks by Hamas. Standing in front of the rocket shells, Mr. Obama declared: "If somebody was sending rockets into my house where my two daughters sleep at night, I'm going to do everything in my power to stop that. And I would expect Israelis to do the same thing." This heartfelt statement sealed the deal for many supporters of Israel.
Now, some of them apparently have voters' remorse. According to Malcolm Hoenlein, executive vice chairman of the Conference of Presidents of Major American Jewish Organizations, "President Obama's strongest supporters among Jewish leaders are deeply troubled by his recent Middle East initiatives, and some are questioning what he really believes." I hear the same thing from rank-and-file supporters of Israel who voted for Mr. Obama.
Are these fears justified? Rhetorically, the Obama team has definitely taken a harsher approach toward Israel compared to its tone during the campaign. But has there been a change in substance about Israel's security? In answering this question, it is essential to distinguish between several aspects of American policy.
First there are the settlements. The Bush administration was against expansion of West Bank settlements, but it was willing to accept a "natural growth" exception that implicitly permitted Israel to expand existing settlements in order to accommodate family growth. The Obama administration has so far shut the door on this exception.
I believe there is a logical compromise on settlement growth that has been proposed by Yousef Munayyer, a leader of the American-Arab Anti-Discrimination League. "Obama should make it clear to the Israelis that settlers should feel free to grow their families as long as their settlements grow vertically, and not horizontally," he wrote last month in the Boston Globe. In other words, build "up" rather than "out." This seems fair to both sides, since it would preserve the status quo for future negotiations that could lead to a demilitarized Palestinian state and Arab recognition of Israel as a Jewish one -- results sought by both the Obama administration and Israel.
A majority of American-Jewish supporters of Israel, as well as Israelis, do not favor settlement expansion. Thus the Obama position on settlement expansion, whether one agrees with it or not, is not at all inconsistent with support for Israel. It may be a different position from that of Prime Minister Benjamin Netanyahu, but it is not a difference that should matter to most Jewish voters who support both Mr. Obama and Israel.
The differences that would matter are those -- if they exist -- that directly impact Israel's security. And in terms of Israel's security, nothing presents a greater threat than Iran.
The Obama administration consistently says that Iran should not be allowed to develop nuclear weapons. But prior to the current unrest in the Islamic Republic, White House Chief of Staff Rahm Emanuel frightened many supporters of Israel in May by appearing to link American efforts to stop Iran from developing nuclear weapons to Israeli actions with regard to the settlements.
This is a disturbing linkage that should be disavowed by the Obama administration. Opposition to a nuclear Iran -- which would endanger the entire world -- should not be dependent in any way on the issue of settlement expansion.
The current turmoil in Iran may strengthen the Obama administration as it seeks to use diplomacy, sanctions and other nonmilitary means to prevent the development of nuclear weapons. But if these tactics fail, the military option, undesirable and dangerous as it is, must not be taken off the table. If the Obama administration were to shift toward learning to live with a nuclear Iran and attempt to deny Israel the painful option of attacking its nuclear targets as a last resort, that would be troubling indeed. Thankfully, the Obama administration's point man on this issue, Dennis Ross, shows no signs of weakening American opposition to a nuclear-armed Iran.
A related threat to Israeli security comes from Iran's proxies, Hezbollah and Hamas. For years, these terrorist groups have disrupted life in Israel by firing rockets at civilians. The range of their weapons now extends to Israel's heartland, including Tel Aviv. The Israeli Defense Forces must retain the ability to prevent and deter rocket fire, even if it comes from behind human shields as it did in southern Lebanon and Gaza. There is no evidence of any weakening of American support for Israel's right to defend its children from the kind of rocket attacks candidate Obama commented on during his visit to Sderot.
There may be coming changes in the Obama administration's policies that do weaken the security of the Jewish state. Successful presidential candidates often soften their support for Israel once they are elected. So with Iran's burgeoning nuclear threat, it's important to be vigilant for any signs of weakening support for Israel's security -- and to criticize forcefully any such change. But getting tough on settlement expansion should not be confused with undercutting Israel's security.
Mr. Dershowitz is a law professor at Harvard. His latest book is "The Case for Moral Clarity" (Camera, 2009).