Israel‘s military operation against Iran‘s nuclear program began with speed and impressive strategic effect on Friday. Still, the United States will face significant military and counterterrorism challenges as the conflict continues.

Israel’s early successes are significant. Numerous high-ranking Iranian nuclear scientists and military officials, including the heads of the Iranian military, the Islamic Revolutionary Guard Corps, and the Guard’s Quds Force foreign covert action unit, were killed. The death of the latter official, Esmail Qaani, is manifestly good news for the U.S. — Qaani plotted numerous assassination attempts against top U.S. officials, including President Donald Trump. Numerous Iranian nuclear facilities have also been struck, and further Israeli military action is expected over the weekend and into next week.