Steven Cook calms fears that Iranian nuclearization would cause its neighbors to follow suit:

Most important to understanding why the Middle East will not be a zone of unrestrained proliferation is the significant difference between desiring nukes and the actual capacity to acquire them. Of [Turkey, Saudi Arabia, and Egypt], the one on virtually everyone's list for possible nuclear proliferation in response to Iran is Turkey. But the Turkish Republic is already under a nuclear umbrella: Ankara safeguards roughly 90 of the United States' finest B61 gravity bombs at Incirlik airbase, near the city of Adana.