Israel's 'Iron Dome' Can't Stop a Suitcase Bomb—David Frum

In my column for CNN, I explain why Israel's new missile-defense system will not be enough to protect the country from a nuclear Iran:

Since 2001, Israel has responded to attacks by deploying ever-more effective technological systems: first the security fence to halt the entry of suicide bombers; now Iron Dome to stop short-range rockets; and in time, the Arrow anti-ballistic missile system against longer-range missiles.

These innovations have defeated and deterred violence and saved many lives.

But these innovations are also subject to inherent weaknesses.

The rockets launched from Gaza are armed only with explosives and shrapnel. When Iron Dome misses -- and it does sometimes miss -- the Gaza rockets kill and maim only within a very limited radius.

The fence also fails sometimes. Last year for example, a British citizen was killed and 50 people wounded by a suicide bombing near the Jerusalem convention center. Yet as with the Gaza rockets, the lethality of suicide bombings is inherently limited. Israel does not need to reach 100% success to defeat the terrorism threat.

Suppose, however, that the rockets carried nuclear payloads, or that the suicide bombers had access to radioactive materials. Then a 90% success rate would not nearly suffice.

Iran's nuclear program threatens to upend the strategic calculus of the past decade, to overwhelm all Israeli countermeasures to protect Israel's population.

A nuclearized Iran does not imply "incomplete" security for Israel. It would expose Israel to absolute insecurity.

Click here to read the full column.