During the Cold War and the Red Scare, few questions echoed through American political discourse as recurrently as â€œWho lost China?â€ The inquiry presumed its own answer. It was not Mao Zedong who won the civil war; it was not the corrupt and incompetent Chiang Kai-Shek who lost it. Someone American, someone perfidious, had allowed China to go Communist. The question destroyed the career of a generation of â€œChina hands,â€ as the American diplomats expert in the nation were known. It led the United States not only to deny diplomatic recognition to Mao's regime but to refuse it a seat in the United Nations. No domestic politician put the suspicious and paranoid political climate to more effective use than Richard Nixon, and none struck American liberals as more despicable. Yet Nixon's Red-baiting past served as the unlikely prologue for his opening to China in the early 1970s. The very fact that a president with flagrantly anti-Communist credentials met with Mao and Zhou Enlai and commenced the process to normal diplomatic relations silenced what surely would have been the cries of treason had any liberal or Democrat embarked on the identical policy. SO, AS a middle-aged man old enough to remember, I naturally recall the Nixon scenario in observing the way Ariel Sharon has redefined the landscape for American Jews on the issue of Israel and the Palestinians. Like Nixon, he has leveraged his right-wing credentials to establish a new centrism here, something that appears stable in part because it is so utterly unsentimental. Like Nixon, he has confounded his detractors by contradicting his former self. No Israeli leader, after all, put more cracks in the edifice of American Jewish support for Israel than the earlier incarnation of Ariel Sharon. His prosecution of the Lebanon War into the heart of Beirut, his indirect culpability in the massacre of Palestinians in the Sabra and Shatilla refugee camps, his central role in the settlement movement all these provoked the first meaningful criticism of Israel by American Jews. Bold, aggressive, reckless, Sharon embodied the aspects of Israeli character that American Jews from their positions of physical security and material comfort most crave and most reject. Not only were Sharon's wartime actions controversial, so was his very personality. In the wake of the Lebanon invasion, polls by the respected sociologist Stephen M. Cohen found that for the first time a plurality of American Jews endorsed the concept of â€œterritorial compromiseâ€ in the West Bank and Gaza, which certainly was not the policy of Menachem Begin's ruling Likud. While this shift in opinion did not afford the drama and passion of public demonstrations in Israel itself, which forged the Peace Now movement, the American dissent ruptured decades of virtually unanimous and unquestioning backing for Israel, most prominently during the 1967 and 1973 wars. And if American Jews required a refresher course in why Sharon discomfited so many of them, he provided it with his walk atop the Temple Mount five years ago, supplying a neat pretext for Yasser Arafat to launch the second intifada. DURING THE Oslo period, when Sharon appeared to be yesterday's man, American Jewry had divided on the land-for-peace issue in an asymmetrical way. Most polls found that 60 percent or 70% of American Jews supported the concept, which was a particularly safe stand to take when it meant aligning with the prime minister, Yitzhak Rabin. Yet this majority was largely passive, rarely motivated to act on behalf of its idealism, and it was out-organized and out-maneuvered by the minority on the American Jewish right wing, for whom opposing Oslo was a priority task. In retrospect, one can also see that the epochal optimism associated with Oslo the vision of open borders, economic cooperation, and cultural exchange with the Palestinians made American Jewish support a rickety structure. When all those hopes died in the Ramallah police station and outside the Dolphinarium disco, the liberal and moderate bulk of American Jews lost their foundation. Some moved to the political Right; many more were gripped by a paralysis, a crisis of faith. The longtime foes of Oslo, meanwhile, had their season of saying, â€œWe told you so.â€ Now, of all people, Ariel Sharon has rattled the existing order. In Israel, he may well have followed the public more than led it in building the separation barrier and disengaging from Gaza. In America, though, Jews prefer to be â€œtwo steps behind rather than two steps ahead of the prime minister on security issues,â€ as Steven Bayme, director of the American Jewish Committee's Koppelman Institute of American Jewish-Israel Relations, put it. Here Sharon has driven the Jewish discussion and the Jewish realignment. As the architect of Gaza withdrawal, Sharon rendered the policy nearly invulnerable to attack from the American Jewish Right. Who exactly was going to call him weak on security? At the same time, the liberals and moderates had to come to terms with the reality that the so-called â€œbulldozerâ€ of the settlement enterprise had applied the same force of will to undoing one large chunk of it. Who was going to complain about results? There is very little optimism in this American Jewish center, and that augurs well for its sturdiness. As Bayme points out, two sober assessments the need for defensible borders and the looming threat of an Arab majority between the river and the sea informed the Gaza pullout. Sharon has not promised the jubilee year, and so when Palestinian violence occurs it will not dash any sweet illusions. The American Jewish center, like its Israeli counterpart, is built to hold. With this column, Samuel G. Freedman becomes a regular contributor to The Jerusalem Post. A professor of journalism at Columbia University, Freedman is the author of books including Jew vs. Jew: The Struggle for the Soul of American Jewry.