JERUSALEM — Iraq may still be three to five years away from producing a deliverable nuclear warhead, Israeli experts say, but it has already developed missiles that can reach targets throughout the Middle East.

Iraq's President Saddam Hussein, they say, is embarked on a "very aggressive" nuclear weapons program.

"Hussein is trying to acquire all kinds of technology transfer from abroad to develop Iraq's nuclear weapons capability," Dr. Dore Gold said at the Jaffee Center for Strategic Studies at Tel Aviv University. "We at the center think that it will take at least five years to obtain that nuclear capability."

Once Iraq has such weapons, Gold said, it will "be able to assert enormous power with its huge conventional forces, because it will have a nuclear deterrent against other nations."

"A major reason Iraq wants high oil prices--and Kuwait's oil," he said, "is to finance a crash nuclear program. It is a very aggressive program."

Another Israeli strategic thinker, Prof. Gerald M. Steinberg of Tel Aviv's Bar-Ilan University, suggested that Iraq could have a nuclear weapons capability in as little as three years.

"They are making an all-out effort at development facilities spread around Iraq," he said.

Iraq has converted its Soviet-supplied Scud missile, which has a range of about 175 miles, into a weapon with a much longer range. According to military analysts here, Iraq's Scuds are capable of delivering a warhead to targets up to 1,000 miles away.

Israeli experts say Iraq's nuclear program is being carried out on a catch-as-catch-can basis, with the government seeking to develop some nuclear components locally and buying whatever it can on the international market.

Intelligence sources in Israel believe that Iraq is trying to build a centrifuge to produce uranium fuel and at the same time looking for ways to produce plutonium with reactors. Uranium and plutonium are both used in nuclear weapons.

Iraq's major effort to develop a nuclear missile capacity was set back dramatically in 1981, when Israeli bombers destroyed the French-built Osirik reactor south of Baghdad.

Sources here believe that even with French assistance--and, ironically, Saudi Arabian financing--the Osirik reactor is still not in operation.

Iraq has two smaller research reactors, sources in Israel say, but it is questionable whether they could produce any plutonium.