The ongoing turmoil in Egypt has focused attention on whether Israel can continue to rely on its peace treaties with Cairo and Amman. Military analysts have described these treaties as the main 'linchpin' of Israel's security in a hostile neighborhood. Some have gone so far as to suggest that, without an ability to rely on these treaties, Israel would be left without an effective defense to ensure its very existence.

Yet, while peace with Egypt and Jordan indeed has been a keystone of Israel's security during the last several decades, one shouldn't lose sight of the fact that Israel has an even greater ace in the hole, a deterrent transcending all the others arrows in its quiver-- its undeclared nuclear arsenal.

Israel's alleged arsenal of nuclear weapons hovers over the direst threats that can be conjured up by military planners. Such as:

Regardless of its peace treaties with Jordan and Egypt, what happens if Hezbollah, with its tens of thousands of rockets in Lebanon, and Hamas, with its tens of thousands of rockets in Gaza, were to launch all-out simultaneous attacks against the Jewish state? Or how would Israel confront an even greater peril -- if radical regimes in Jordan and Egypt were to join in the fray?

Adding even greater complexity to such eventualities -- how could Israel respond with nuclear weapons against attacks with conventional weapons? How could Israel, under such circumstances, justify a first-strike nuclear strategy?

History provides a few ready answers. The age of nuclear weaponry was ushered in 1945 when Harry Truman unleashed two nuclear strikes on Japan -- not to ensure the continued existence of the United States -- the U.S. at that point was nowhere near the abyss -- but to shorten the war and save hundreds of thousands of lives.

During the Cold War, NATO developed a first-strike nuclear strategy to checkmate superior Soviet conventional forces. NATO called it "flexible response," but its basic premise was well known. NATO did not have an adequate conventional-weapons deterrent. The Soviets had twice as many tanks and far more troops.

Repelling a potential Soviet attack with conventional weapons was a loser for NATO. So U.S. defense officials announced that NATO would not launch a first strike against any country without a nuclear arsenal. This, however, was PR window-dressing. "Flexible response" was aimed as a warning and deterrent to Moscow, which had an ample supply of nukes, not to its satellites. Despite great domestic pressures to renounce a nuclear first-strike option, Washington and NATO stood fast in keeping it front and center in the Western alliance's strategic thinking.

So all during the Cold War, the world lived with NATO's first-strike nuclear playbook, which as it turned out, proved to be a highly successful deterrent that kept the peace in Europe.

For its part, Israel -- when it comes to its very survival -- has like NATO its own version of a first-strike nuclear deterrent. After the 1973 Yom Kippur War, there were reports that Golda Meir -- during a moment of highest peril from the joint Egyptian-Syrian blitzkriegs -- contemplated use of nuclear weapons.

Today, Israel has a growing fleet of rocket-firing submarines and other potential nuclear delivery systems, including its Air Force. Should Hezbollah and Hamas ever be tempted to launch an all-out, coordinated attack authorized and prompted by Iran, they must know that Israel has its own ace in the hole, its own ultimate deterrent that could devastate not only Lebanon and Gaza, but a good chunk of Iran as well.

Such scenarios, I know, do not make for happy reading. But Israel has proved time and again -- by bombing Saddam's nuclear reactor in Iraq and Assad's nuclear facility in Syria -- that when the chips are down, it will not hesitate to resort to pre-emptive strikes. So far, Israel has managed to accomplish this with conventional weapons.

But Israel's enemies should be reminded that it has in the wings presumably a much more formidable deterrent that far transcends in importance its highly valued and rightly appreciated peace treaties with Jordan and Egypt.

LEO RENNERT