An old argument is resurfacing in the Iran debate: that a nuclear-armed Iran would make the Middle East calmer, not more dangerous — a claim most Western governments reject outright.

• The idea traces to Kenneth Waltz, who argued shortly before his death that an Iran with nuclear weapons would feel secure enough to stop stirring up trouble abroad.
• The logic is that countries with the bomb stop fighting each other directly, because the risk is too high.
• India and Pakistan are the test case — supporters point to fewer full wars between them since Pakistan went nuclear.
• The broader version goes further: more nuclear powers in the region would mean a more stable region, not a more explosive one.

Outlook: This thinking stays on the fringe of policy, but expect it to keep surfacing as pressure on Iran's nuclear program continues.