Act of war?

(WaPo) — In November, the tide of daily cable traffic to the U.S. Embassy in Azerbaijan brought a chilling message for Ambassador Matthew Bryza, then the top U.S. diplomat to the small Central Asian country. A plot to kill Americans had been uncovered, the message read, and embassy officials were on the target list.

The details, scant at first, became clearer as intelligence agencies from both countries stepped up their probe. The plot had two strands, U.S. officials learned, one involving snipers with silencer-equipped rifles and the other a car bomb, apparently intended to kill embassy employees or members of their families.

Both strands could be traced back to the same place, the officials were told: Azerbaijan’s southern neighbor, Iran.

The threat, many details of which were never made public, appeared to recede after Azerbaijani authorities rounded up nearly two dozen people in waves of arrests early this year. Precisely who ordered the hits, and why, was never conclusively determined. But U.S. and Middle Eastern officials now see the attempts as part of a broader campaign by Iran-linked operatives to kill foreign diplomats in at least seven countries over a span of 13 months. The targets have included two Saudi officials, a half-dozen Israelis and — in the Azerbaijan case — several Americans, the officials say.

In recent weeks, investigators working in four countries have amassed new evidence tying the disparate assassination attempts to one another and linking all of them to either Iran-backed Hezbollah militants or operatives based inside Iran, according to U.S. and Middle Eastern security officials. An official report last month summarizing the evidence cited phone records, forensic tests, coordinated travel arrangements and even cellphone SIM cards purchased in Iran and used by several of the would-be assailants, said two officials who have seen the six-page document.