The Wisconsin congressman, speaking in Washington at the Value Voters Summit, said the killing of four U.S. diplomats, including the ambassador to Libya -- as well as attacks this week on U.S. embassies and consulates -- illustrate a lack of leadership on Obama's part.
"Look across that region today, and what do we see?," Ryan said. "The slaughter of brave dissidents in Syria. Mobs storming American embassies and consulates. Iran four years closer to gaining a nuclear weapon. Israel, our best ally in the region, treated with indifference bordering on contempt by the Obama administration.
"Amid all these threats and dangers, what we do not see is steady, consistent American leadership."
Ryan said U.S. foreign policy "needs moral clarity and firmness of purpose. Only by the confident exercise of American influence are evil and violence overcome."
"That is how we keep problems abroad from becoming crises," he said. "That is what keeps the peace. And that is what we will have in a Romney-Ryan administration."
Ryan, a Catholic, also attacked Obama on abortion and on his economic record. He praised the Republican presidential nominee, Mitt Romney.