GOP vice presidential nominee Paul Ryan delivered his sternest rebuke yet to President Obama’s foreign policy Friday morning, telling an annual conference of social conservatives that the administration gave mixed signals in response to this week’s attacks on United States diplomatic missions in Egypt and Libya and that Obama has alienated America from its allies in the Middle East.

Ryan also took aim at the administration for the contraception mandate in the national health-care law, making note of his own Catholic faith and echoing GOP presidential nominee Mitt Romney in framing the provision as an attack on religious liberty.

And Ryan introduced a new line of attack against Obama, telling the crowd that “the only kind of debate he can win” is “against straw-man arguments.”

“No politician is more skilled at striking heroic poses against imaginary adversaries,” Ryan said. “Nobody is better at rebuking nonexistent opinions. Barack Obama does this all the time, and in this campaign we are calling him on it.”