Israeli forces have just killed and wounded hundreds of Palestinians in the very neighborhoods in the Gaza Strip where I have worked for decades to help establish clinics.

As I walk the orderly San Francisco streets, Gazans struggle to clear the rubble on theirs. I know that my tax dollars have helped pay for the Israeli planes that attacked densely packed Gaza cities, tore bodies asunder and sent schoolchildren fleeing in fear.

During my stay in Gaza last month, Palestinians expressed little hope that an Obama administration would bring peace or security. The main topic of conversation was the suffocating impact of Israel's siege on the daily life of Palestinians there.

Although Israel withdrew its soldiers and settlers from Gaza in 2005, it has continued, like a warden of a large-scale prison, to control access into and out of Gaza by land, sea and air. As such, Israel remains an occupying power in Gaza and, according to international law, is responsible for the welfare of its civilian population.

Israel imposed the siege on Gaza last year, severely restricting the food, medical supplies and fuel that can enter. It has been roundly condemned by the United Nations and international human rights organizations for the resulting humanitarian catastrophe. More than 80 percent of Gazans have come to depend on food assistance to survive. The health system is crippled by lack of medicines and electricity to run life-saving machines.

U.N. Relief and Works Agency Commissioner-General Karen Koning AbuZayd warned earlier this year that "Gaza is on the threshold of becoming the first territory to be intentionally reduced to a state of abject destitution."

The suffocation of Gaza continued despite a six-month cease-fire that Palestinians had honored. Israel violated that agreement by maintaining the siege of Gaza, and, on Nov. 4, by raiding Gaza and killing a Palestinian. The attack triggered a response from Palestinians, who fired crude rockets into Israel, killing one Israeli.

Israel now uses these crude rocket attacks as justification for bombing, saying it is targeting security compounds and rocket-launching bases.

Despite these claims, the Times of London reported that "Children on their way home from school and policemen parading for a graduation ceremony were the principal victims."

A government interested in peace and security does not violate a truce as it comes up for renewal. Israel's actions are not self-defense.

Rather, Israel's deliberate truce violations, siege and recent mauling of Gaza are calculated to undermine Hamas, which won democratic elections in the Palestinian territories in 2006 and controls Palestinian Authority institutions in Gaza. There is one word for the deliberate killing of civilians for political objectives: terrorism. It should apply equally to non-state actors and to states.

President-elect Barack Obama has an opportunity to introduce desperately needed change in America's Middle East policy. Nothing would accomplish more than for Obama to speak out clearly against Israel's terrorism in Gaza. He should clarify that while all governments have the right to self defense, this cannot include the wanton bombardment of heavily populated civilian areas.

For too long, American support of Israel has come without condition. Billions of our tax dollars have supported a state that betrays American values and engages in policies that harm America's image and interests abroad. Millions of Arabs and Muslims are glued to television sets right now. They are watching scenes of Palestinian men, women and children bathed in blood, aware that American-supplied F-16 fighter jets delivered the bombs. Imagine the difference if, instead, they saw an American leader declare that Palestinians - like Israelis - have the right to live in freedom and security. Imagine if those American planes were delivering much-needed food and medicine to people in Gaza.

My friends in Gaza hold little hope that the Obama administration will bring this kind of change. But I hope they are wrong. I hope that the best of America - the America that will inaugurate an African American president - will be reflected in our policy toward Israel and the Palestinians.