A Lebanese-American man nabbed in Detroit on charges that he was on his way to fight for Hezbollah and Syria is raising new concerns about trained jihadists hiding in the United States and the possibility they will turn their fire on America, according to officials and Hill leaders.

According to National Intelligence Director James Clapper, there are about 50 foreign-trained terrorist fighters living in the United States who “have aspirations for attacks on the homeland” once their work in Syria is done.

Surprisingly, the federal government doesn’t have all the tools needed to fight the potential traitors.

That has prompted Rep. Frank Wolf, R-Va., to push for new legislation to prevent terrorist groups operating in Syria from helping to radicalize Americans by restricting unsanctioned travel to Syria by Americans.

In the Detroit case, a 22-year-old Dearborn Heights, Mich., man was arrested Sunday at Detroit Metro Airport as he readied for a flight to Beirut, Lebanon, through Paris. He was to return to the U.S. on May 3.

The government said that Mohammad Hassan Hamdan planned to fight with Hezbollah on behalf of the Syrian government, which is opposed by the administration.

Wolf’s bill would make it easier for federal authorities to block traveling to terrorist countries and supplying them with “material support.” The bill calls for administration to target terror states as a “country of conflict concern,” which would then trigger travel and trade sanctions.

He introduced his bill in response to concerns aired by Clapper about the threat in the United States of Americans trained to fight in terror complexes overseas.

“This bill is a smart, targeted tool for the U.S. to prevent radicalization of U.S. nationals and keep our homeland safe,” Wolf said. “It’s necessary because it is currently difficult for law enforcement to determine whether U.S. nationals returning from Syria under questionable circumstances were involved in fighting and working with foreign terrorist groups.”

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com.