Home Is No Haven for Iran’s Regime

The killing of Iranian nuclear scientist Mohsen Fakhrizadeh should be a message to Joe Biden and his nascent administration. Even as Iranian intelligence has pushed aggressively to expand its external influence via regional proxies, its domestic counterintelligence capabilities have significantly weakened. This is only the latest in a series of attacks that underscore the extent to which foreign intelligence services have been able to penetrate the country. Such attacks undermine the regime and could encourage domestic unrest. Mr. Biden should factor in this weakness as he prepares to negotiate with Tehran.

State…