Trump can't ignore Russia's actions in Persian Gulf, former U.S. ambassador says

He suggested that Moscow’s cooperation with Iran will change Trump’s approach to the Kremlin.

"Trump has ignored or tried to ignore Russia's hostile actions against our soldiers, our pilots and our friends and allies in the Middle East," Herbst said. "But I don't think he can keep doing that."

Herbst said Russian intelligence enabled Iran to strike an air base in Riyadh, Saudi Arabia, wounding about 10 U.S. service members and destroying a valuable E-3 AWACS aircraft. He also said the information helped Iran attack U.S.-made radar stations across the region.

"Those were very important military targets for Iran. So at some point there has to be a reaction," Herbst said.

He added that Washington has at times softened its stance toward Moscow because of concerns about Russia's actions in the Middle East, but he said it is unlikely the United States will continue to maintain that approach.

Herbst served as U.S. ambassador to Ukraine from 2003 to 2006 and is director of the Eurasia Center at the Atlantic Council.