WASHINGTON – Syria’s stockpile of chemical weapons could be a greater threat after that nation’s president leaves power and could end up targeting Americans at home, lawmakers warned Sunday as they considered a U.S. response that stops short of sending military forces there.

U.S. officials last week declared that the Syrian government probably had used chemical weapons twice in March, newly provocative acts in the 2-year-old civil war that has killed more than 70,000 people and displaced hundreds of thousands more. The U.S. assessment followed similar conclusions from Britain, France, Israel and Qatar – key allies eager for a more aggressive response to the Syrian conflict.

President Barack Obama has said Syria’s likely action – or the transfer of President Bashar Assad’s stockpiles to terrorists – would cross a “red line” that would compel the United States to act, but said he didn’t have enough information to order aggressive action.

Lawmakers sought to remind viewers on Sunday of Obama’s declaration while discouraging a U.S. foothold on the ground there.

“The president has laid down the line, and it can’t be a dotted line. It can’t be anything other than a red line,” said House Intelligence Committee Chairman Rep. Mike Rogers, R-Mich. “And more than just Syria, Iran is paying attention to this. North Korea is paying attention to this.”

Added Sen. Saxby Chambliss, R-Ga.: “For America to sit on the sidelines and do nothing is a huge mistake.”

One of Obama’s chief antagonists on Syria, Sen. John McCain, R-Ariz., said the United States should go to Syria as part of an international force to safeguard the chemical weapons. But McCain added that he is not advocating sending ground troops to the nation.

“The worst thing the United States could do right now is put boots on the ground on Syria. That would turn the people against us,” McCain said.