(CNN) -- As Iran rushes ahead with its nuclear program, some foreign policy thinkers urge Israel to accept that it must live with "incomplete" security. On Monday morning, 200,000 Israeli children spent the morning in bomb shelters rather than classrooms, as rockets from Gaza barraged southern Israeli cities. That would seem to qualify as security "incomplete" enough to satisfy anybody. Israel has met the barrage with a new defense system, named Iron Dome. Iron Dome senses rocket launches. Its computers assess which rockets are headed toward populated areas, then it fires missiles to intercept the incoming rockets. According to the Israel Defense Forces, Iron Dome has achieved a success rate of more than 90% when fired. Since Friday, Palestinian militants have fired more than 170 rockets at Israeli cities, but as yet, no Israeli civilians have been killed.
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Israel reported 90-plus percent success in fending off incoming rockets
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David Frum says the "Iron Dome" system is useful for defending against Gaza militants
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He says an Iranian nuclear weapon would change the calculation
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Frum: Partial security isn't enough when the threat is mass annihilation
Iran's nuclear program threatens to upend the strategic calculus of the past decade, to overwhelm all @placeholder countermeasures to protect Israel's population.