Israel is reported to be seeking U.S. loan guarantees of $5 billion to finance the purchase of the advanced weapons systems the U.S. administration has offered the Jewish state under a $10 billion package for its Middle East allies.

These include AGM-88 HARM anti-radiation missiles made by the Raytheon Corp., that can knock out air-defense radar systems and Boeing KC-135 Stratotankers that will greatly extend the reach of Israel's strike jets.

In the long term, the procurement of the U.S. arms package will be financed by U.S. military aid which in fiscal 2013 will total $3.1 billion, the highest total for any U.S. ally.

The bridging loans, the U.S. journal Defense News reported, would be arranged with U.S. commercial banks to cover the intermediary period. The weekly said both Israelis and U.S. sources expect a response concerning the loans request by this summer.

Israeli Defense Minister Moshe Yaalon pressed U.S. Defense Secretary Chuck Hagel on this when he visited Washington in mid-June, Israeli sources say.

The unprecedented upgrade of U.S. 0Israel security cooperation followed the July 17, 2012, passing of U.S. President Barack Obama's United States-Israel Enhanced Security Cooperation Act.

It was widely supported by Republicans and Democrats and extended until the end of 2014 the funding provided by the U.S. government placing emergency U.S. arms stockpiles on Israeli soil in case of war.

The Israel segment of the military aid package, which also includes weapons systems for Saudi Arabia and the United Arab Emirates, covers advanced radars for the Israeli air force's F-15I aircraft and up to eight V-22 Osprey tilt-rotor aircraft manufactured by Bell Boeing.

All these systems would significantly enhance Israel's capability to launch pre-emptive strikes against Iran's nuclear infrastructure, which Prime Minister Binyamin Netanyahu has repeatedly threatened to unleash.

The reasoning behind offering Israel such a cornucopia of advanced weapons systems and long-range capabilities would seem to be to reassure Israel that the United States stands behind the Jewish state, but does not want it to launch any attack on Iran while the diplomatic efforts and an international sanctions regime are in play.

The AGM-88 missile, first used in combat in March 1986 by U.S. jets against a Libyan SA-5 surface-to-air missile site in the Gulf of Sidra, would be a substantial upgrade of Israel's current AGM-78 anti-radiation missiles.

The advanced radars for Israel's 25 F-15I Ra'ams and the Ospreys, aircraft which can land like a helicopter and each carry two dozen fully equipped Special Forces soldiers over long distances at aircraft speeds, also would provide greater offensive capabilities for any operation against Iran.

The Osprey "is the ideal platform for sending Israeli Special Forces into Iran" observed Kenneth Pollack, a former Central Intelligence Agency analyst who is currently at the Brookings Institution's Saban Center for Middle East Policy.

The unique tilt-rotor aircraft would give Israel the capability of inserting special ground forces to either attack Iranian facilities such as the new uranium enrichment plant buried deep inside a mountain at Fordow, outside the holy city of Qom south of Tehran, that may be resistant to even the heaviest U.S.-made bunker-buster bombs designed to penetrate hardened underground facilities, or to "paint" targets with lasers for the attacking aircraft.

Jonathan Schanzer, executive director of the Foundation for the Defense of the Democracies in Washington, said the U.S. package conformed to an Israeli wish-list presented to the Pentagon that included some items that were not discussed publicly, presumably because they were intended for an assault on Iran.

Details of the arms package have yet to be revealed. It's not known how many weapons and aircraft will be sent to the three countries, nor are delivery dates.

"The timeline of delivery will dictate when Israel can use these weapons," observed the U.S. global security consultancy Stratfor.

Although it's not clear how many KC-135 tankers Israel will get, it's expected to be enough to sustain a major air strike that would most likely involve all of the air force's 25 F-15Is and 100 F-16I Sufas, its entire strategic strike force, and its seven KC-707 and four KC-130H tankers.

The current tanker force would not be able to support a force of that size receiving at least two mid-air refuelings during the 1,000-mile flights to and from the targets.