Whether or not one believes going to war in Afghanistan was an appropriate U.S. response to the crime against humanity committed on September 11, 2001, it is a far different scenario than that faced by Israel.
Israel has every right to arrest and try anyone attempting to attack civilians inside the country. But it does not have the right to occupy a neighboring country, and if it is serious about ending attacks on civilians, it must be serious about ending that occupation.
Israel is occupying Palestinian land and harshly controlling Palestinian lives; Palestinian violence, even those extreme and ultimately illegal actions such as lethal attacks on civilian targets, is a response to that occupation. Israel does not have the right, under international law or United Nations resolutions, to continue its occupation, let alone to use violent methods to enforce it.
Since September 11, Israeli politicians led by Prime Minister Ariel Sharon have ratcheted up their rhetoric equating the U.S. "war on terrorism" in Afghanistan with Israeli assaults in the occupied Palestinian territories. Immediately after the September 11 attacks, former Prime Minister Binyamin Netanyahu blurted out, "It's very good." Then, editing his words, he added, "Well, not very good, but it will generate immediate sympathy."
Israel has also used the escalating fear of terrorism in the U.S. after September 11 to increase its support (financial, diplomatic and political) from Congress and the American people. In fact, the Bush administration's post-September 11 embrace of the extremist Sharon government has allowed new threats of even more dire Israeli attacks against Palestinians--up to and perhaps including forced "transfer" of Palestinians out of the occupied territories--to go unchallenged by Washington and to become part of normal political discourse inside Israel.