The devastating Israeli firepower, unleashed largely on Palestinian civilians in Gaza during two weeks of fighting, is the product of advanced US military technology.

The US weapons systems used by the Israelis  including F-16 fighter planes, Apache helicopters, tactical missiles and a wide array of munitions  have been provided by Washington mostly as outright military grants.

The administration of President George W. Bush alone has provided over 21 billion dollars in US security assistance over the last eight years, including 19 billion dollars in direct military aid as freebies.

"Israel’s intervention in the Gaza Strip has been fueled largely by US supplied weapons paid for with US tax dollars," says a background briefing released Thursday by the Arms and Security Initiative of the New York-based New America Foundation.

"The Bush administration has been unwilling to use its considerable influence  as Israel’s major military and political backer  to dissuade the government in Tel Aviv from its pattern of claiming self-defense while perpetrating collective punishment, human rights violations and undertaking massively disproportionate attacks that harm and kill civilians," Frida Berrigan, senior program associate at the New America Foundation, told IPS.

Besides military aid, the United States has contracted more than 22 billion dollars in arms sales to Israel in 2008 alone, including a proposed deal for 75 F-35 Joint Strike Fighters, nine C-130J-30 military transport aircraft and four combat ships.

"So, when Israeli forces engage in combat in Gaza or the West Bank, they are more often than not using US-designed systems that were either made in the United States or produced under license in Israel," says the New America Foundation.

The two-week military onslaught has resulted in the deaths of over 700 Palestinians, including more than 300 civilians, mostly victims of US weaponry.

In comparison, the Israeli death toll is about seven soldiers and four civilians, primarily due to "friendly fire", or victims of rocket attacks by Hamas.

Mouin Rabbani, contributing editor at the Washington-based Middle East Report, says the intimacy of the US-Israeli military relationship, and the frequency with which Israel launches wars, means that the Israeli military also performs the function of testing newly-developed weapons systems in actual warfare, which is of value to both Israel and the United States.

"Twice over, in fact, because less effective versions of these same weapons systems are subsequently sold at hugely inflated prices to Arab states, which effectively subsidizes the US weapons industry and US military grants to Israel," he told IPS.

Tracing historical links, Rabbani said Israel replaced South Vietnam as the primary recipient of US foreign military aid in the 1970s and has maintained that status ever since.

With consistently fewer exceptions over the years, he pointed out, Israel has the run of the US arsenal, particularly with regard to obtaining new and advanced weapons that are not sold (or, as in the present case, given) to non-NATO (North Atlantic Treaty Organization) allies.

He said that Israel is also permitted to participate in various US weapons development programs, meaning that in addition to weapons deliveries it benefits enormously from the transfer of military technologies.

"Israel also has access to various US intelligence programs and data, and the list goes on for quite some length," Rabbani added.

Last week, US Congressman Dennis Kucinich (Democrat of Ohio) wrote a letter to Secretary of State Condoleezza Rice pointing out that Israel’s use of US weapons in Gaza may constitute a violation of the requirements of the Arms Export Control Act (AECA) of 1976.

The AECA outlines the conditions under which countries may use US weapons systems, primarily for "internal security" or "legitimate self defense".

The letter says that Israeli forces have used US-supplied F-16 fighter planes and Apache helicopters "to precede and to support ongoing ground actions such as the one in which 40 Palestinians were killed while taking shelter in a UN facility."

"Israel is not exempt from international law and must be held accountable," he added.

Berrigan said that with the onslaught about to enter its third week, hundreds of Gazans killed and wounded, 10 Israelis killed and more wounded, Hamas continuing to launch rocket attacks and a grave danger that the conflict will widen to include Lebanon, President-elect Barack Obama "will step into a bed of molten hot quicksand on Jan. 20."

"It will be difficult for the new administration to turn the tide of US-Israeli relations and challenge Israeli exceptionalism, but it is urgently necessary," she added.

Rabbani pointed out that given the level of US military assistance to Israel, the deployment of these weapons in the current onslaught against the Gaza Strip, and US political support for Israel during this crisis, Palestinians could be forgiven for insisting the US shares direct responsibility.

"While I would by no means dismiss the issue of US military transfers to Israel in their various forms and dimensions, the key issue is nevertheless the impunity with which these are used," he added.

It is this impunity, rather than the weapons transfers in and of themselves, that accounts for Israel’s ability to sow widespread death and destruction throughout the Gaza Strip at will.

Asked if there would a change in policy under an Obama administration, Rabbani said: "I don’t see any indication that things are set to change once Obama takes office".

He has attempted to wrap his silence in a cloak of decorum and statesmanship, "claiming he was left with no choice because he is not yet president, then  in view of his constant pronouncements since Nov. 4 regarding the financial meltdown  rather too cleverly in my view elaborated that this only applies to foreign policy."

"So we are supposed to believe that if instead 600 Israelis had been killed by Palestinian suicide bombers in the space of 10 days, or Russia had decided to suddenly advance on Tbilisi, you could still hear a pin drop in Washington? Unlikely."