Anti-Semitism has to be resisted in whatever form it displays itself. Controversy continues over how much the recent terrorist attacks against Jews in Paris reflected anti-Semitism or the war in Lebanon. But a lack of deep concern about these tragedies, whatever their motivation, could betray an underlying anti-Semitism. And the subtler forms of anti-Semitism have to be increasingly resisted in the light of a changed international situation.Many Europeans, for example, have long since stiffened their attitudes toward an Israel whose policies appear to threaten Mideast sources of oil vital to Europe. The temptation to be avoided is a spillover into prejudice against Jews. The challenge is compounded by the aggressive acts of the government of Israel. These must not be allowed to feed a new anti-Semitism or excuse remnants of the old pre-Israel variety. Those appalled by these acts have to prevent reaction to a government from slipping into bias against a people. Fighters against anti-Semitism have plenty of experience dealing with overt attacks by outfits such as the Ku Klux Klan, which keeps trying to rear its ugly head in an American society that has overwhelmingly rejected it. But the battle is harder when anti-Semitism may be tacitly entangled with political, economic, or diplomatic attitudes. The Jews who question the Israel government's policies cannot be anti-Semitic. Nor can the non-Jews who question those policies be assumed to be anti-Semitic. Yet the potentiality is there in human minds where prejudice is never rational. It is up to each individual to reject such silent intrusion as decisively as the noisy bigotry of the Klan.