LOD, Israel — Three days into Josh Warhit’s first-ever visit to Israel, as a 16-year-old on a summer tour, war broke out in Lebanon, which transformed the group’s itinerary — and his life plan. On Tuesday, with talk rampant about the possibility of an imminent Israeli attack on Iran, Mr. Warhit became a citizen of Israel to enlist in its army.

“Our parents were freaking out,” Mr. Warhit, now 22, recalled of that first trip during the war against Hezbollah. “It only made us more thirsty. I love the Jewish people. Love involves commitment. Right now we need people to commit.

“Of course it’s scary,” he added, regarding Iran, “but if you feel a commitment, that’s the thing to do.”

Mr. Warhit, who grew up in New Rochelle, N.Y., and graduated from the University of Rochester after spending several summers in Israel, was one of 127 soldiers-to-be who landed Tuesday morning at Ben-Gurion International Airport here. They arrived after a week of intense media speculation that an Israeli strike on Iran’s nuclear facilities was increasingly likely, though the premier enemy of the moment was not mentioned by name during a hero’s welcome that included a live band, balloon hats and a speech by Prime Minister Benjamin Netanyahu.