Last week, the Middle East nearly plunged into new crisis. The cause was not the civil war in Syria or ethnic strife in Iraq but, again, terrorism from Gaza.

Islamic jihad terrorists fired more than 250 rockets, missiles and mortar shells at civilian neighborhoods in Israel. A million Israelis — including 200,000 schoolchildren — showed courage under fire, and Prime Minister Benjamin Netanyahu displayed restraint. Still, as the fire intensified, the government had to consider ground action.

Israel conducted such an operation in Gaza in 2008, but since then, the entire Middle East has become a powder keg. Syria and Iran reportedly were colluding to exploit Israeli-Palestinian tensions to distract attention from their internal turmoil. Hezbollah leader Hassan Nasrallah has urged his followers to “liberate Jerusalem.” Israel could have to defend itself on multiple fronts.

But the crisis was averted, thanks to a technological marvel. Israel’s Iron Dome anti-missile system succeeded in preventing almost all the terrorist rockets from hitting populated areas in Israel. Progressing from drawing board to deployment in only four years, Iron Dome became the first anti-ballistic system in history to succeed in real combat conditions, intercepting 11 Hamas rockets in April 2011.

That August, Iron Dome destroyed almost 90 percent of the rockets from Gaza, relieving Israel of the need to send troops into the Strip. Iron Dome not only saved lives, it prevented wars.

Designed to take out short-range projectiles, Iron Dome is part of a multitier defense that eventually will include David’s Sling and the Arrow, capable of intercepting medium-range and intercontinental missiles. Israel has developed these systems with the United States — and through the generous assistance of Congress and the Obama administration.

We are profoundly appreciative of this bipartisan support and are deeply grateful for the more than two decades of U.S.-Israel cooperation on missile defense. These pioneering and proven systems represent a win-win accomplishment: Iron Dome, David’s Sling and the Arrow can also help defend U.S. facilities and interests around the world.

Three Iron Dome batteries are currently stationed in southern Israel. They are capable of interdicting multiple targets and of determining whether the rockets will hit urban areas or crash harmlessly into empty fields. The interceptors, which are expensive, are fired only at those rockets deemed likely to cause far more costly damage to civilian areas. As such, the system is economically efficient.

Yet an additional 10 batteries, at least, will be necessary to protect the entire country. Hezbollah’s rockets, for example, would terrorize Israel’s northern cities, while those of Syria and Iran could strike the center.

This need was profoundly demonstrated by last week’s events. By denying Islamic jihad the ability to kill and maim Israeli civilians, we gained precious time for effective Egyptian mediation. Another round of painful house-to-house fighting in Gaza — and possibly a devastating war — was avoided.

But the dangers persist. Indeed, while I was writing this article, another terrorist rocket was launched at Be’er Sheva. Fortunately, Iron Dome was able to intercept and destroy it.

Of course, we remain committed to resolving the conflict based on the principle of two states for two people. But until that is achieved, we have no choice but to rely on both our defensive and offensive capabilities. For America, as well as for Israel, an investment in the Iron Dome system is an investment in diplomacy — helping to create the conditions conducive to peace.

The article originally appeard in Politico on March 18, 2012.