TEL AVIV — Israel has modified American-supplied cruise missiles to carry nuclear warheads on submarines, giving the Middle East's only nuclear power the ability to launch atomic weapons from land, air and beneath the sea, according to senior Bush administration and Israeli officials.
The previously undisclosed submarine capability bolsters Israel's deterrence in the event that Iran -- an avowed enemy -- develops nuclear weapons. It also complicates efforts by the United States and the United Nations to persuade Iran to abandon its suspected nuclear weapons program.
Two Bush administration officials described the missile modification and an Israeli official confirmed it. All three spoke on condition their names not be used.
The Americans said they were disclosing the information to caution Israel's enemies at a time of heightened tensions in the region and concern over Iran's alleged ambitions.
Iran denies developing nuclear weapons and says its nuclear program is solely for generating electricity. Iranian leaders are resisting more intrusive inspections by the United Nations, setting the stage for a showdown in coming weeks.
The U.N.'s International Atomic Energy Agency has given Tehran an Oct. 31 deadline to accept full inspections and prove it has no nuclear arms program.
Arab diplomats and U.N. officials said Israel's steady enhancement of its secret nuclear arsenal, and U.S. silence about it, has increased the desire of Arab states for similar weapons.
"The presence of a nuclear program in the region that is not under international safeguards gives other countries the spur to develop weapons of mass destruction," said Nabil Fahmy, Egypt's ambassador to the United States. "Any future conflict becomes more dangerous."
Late last month, Egypt joined Saudi Arabia and Syria at the U.N. General Assembly in criticizing the U.S. and U.N. for ignoring Israel's weapons of mass destruction while pressuring Iran.
A senior Iranian official raised the same issue at a nonproliferation conference in Moscow in September.
"Stability cannot be achieved in a region where massive imbalances in military capabilities are maintained, particularly through the possession of nuclear weapons that allow one party to threaten its neighbors and the region," said Ali Asghar Soltanieh.
Israel will not confirm or deny that it possesses nuclear arms. Intelligence analysts and independent experts have long known that the country has 100 to 200 sophisticated nuclear weapons.
Israel, India and Pakistan are the only countries with nuclear facilities that have not signed the Nuclear Nonproliferation Treaty, which was initiated in 1968 to stop the spread of nuclear weapons through inspections and sanctions. India and Pakistan also have nuclear bombs.
Iran and Arab states with civilian nuclear programs have signed the treaty. The Arab countries have refused to agree to tougher inspections because Israel will not sign it, U.N. officials said.
"A big source of contention is Israel," said a senior official trying to win acceptance of the additional inspections. "This is a magnet for other countries to develop nuclear weapons."
Israel and its U.S. backers regard its nuclear weapons as a centerpiece of the country's security. The development of the arms over several decades, with tacit U.S. approval, has been rarely mentioned, but it is becoming an increasingly compelling component in discussions about lasting peace in the Middle East.
While not acknowledging the country's nuclear capability, Israeli officials have promised they would not "introduce" such weapons to the Middle East. Israeli and U.S. officials said that means Israel would not launch a first strike using the weapons. They argue that other countries have nothing to fear from Israel's nuclear arms, whereas Israel has everything to fear from its neighbors.Even so, Israel's nuclear stockpile confers military superiority that translates into a high degree of freedom of action, from bombing a suspected terrorist camp in Syria last week to the destruction of an Iraqi nuclear reactor in 1981.
"Nuclear capabilities give the owners enormous political maneuverability which otherwise they do not have," a senior Western security official said.
Since 1969, Washington has accepted Israel's status as a nuclear power and not pressured it to sign the nonproliferation treaty.
"We tolerate nuclear weapons in Israel for the same reason we tolerate them in Britain and France," a senior administration official said. "We don't regard Israel as a threat."
To avoid triggering American economic and military sanctions, U.S. intelligence agencies routinely omit Israel from semiannual reports to Congress identifying countries developing weapons of mass destruction. The Clinton administration even barred the sale of the most detailed U.S. satellite photographs of Israel in an effort to protect that country's nuclear complex and other targets.