A good and impartial essay on the new antisemitism in Wikipedia.
New antisemitism is the concept that a new form of antisemitism has developed in the late 20th and early 21st centuries, emanating simultaneously from the far-left, radical Islam, and the far-right, and tending to manifest itself as opposition to Zionism and the State of Israel. The concept generally posits that much of what purports to be criticism of Israel by various individuals and world bodies, is, in fact, tantamount to demonization, and that, together with an alleged international resurgence of attacks on Jews and Jewish symbols, and an increased acceptance of antisemitic beliefs in public discourse, such demonization represents an evolution in the appearance of antisemitic beliefs.
Proponents of the concept argue that anti-Zionism, anti-Americanism, anti-globalization, third worldism, and demonization of Israel, or double standards applied to its conduct, may be linked to antisemitism, or constitute disguised antisemitism. Critics of the concept argue that it conflates anti-Zionism with antisemitism, defines legitimate criticism of Israel too narrowly and demonization too broadly, trivializes the meaning of antisemitism, and exploits antisemitism in order to silence debate.