Decades of tips and investigations yielded charges against only two people. A combination of missed chances, narrow laws and prosecutors’ limited focus helps explain why.

While the latest tranche of documents about the sex offender Jeffrey Epstein has exposed a deeply American scandal, it is Europe where the aggressive enforcement is taking place.

The killing of Iran’s supreme leader and other top Iranian officials came after close intelligence sharing between the United States and Israel, according to people familiar with the operation.