White House chief of staff Denis McDonough reiterates the president's promise of not using U.S. troops on the ground to fight the Islamic State on Sunday shows. (Divya Jeswani Verma/The Washington Post)

Sen. Lindsey Graham (R-S.C.) was characteristically energetic in offering his opinion of the Obama administration's plan to undermine the Islamic State on Fox News' "Fox News Sunday."

"At the end of the day, ISIL has to be encouraged by what was just said" in Fox host John Roberts's interview with White House chief of staff Denis McDonough, Graham said, using an alternative acronym for the Islamic State. "When the White House tells the world, 'We say what we mean and we do what we say'" — referencing McDonough's defense of the administration plan — "no one believes that anymore." Calling the fight against the Islamic State a "turning point in the war on terror" because the United States is now fighting a "terrorist army," Graham said that "it's going to take an army to beat an army. This idea we'll never have any boots on the ground to defeat them in Syria is fantasy."

"It's delusional in the way they approach this," Graham added.

Sen. Jack Reed (D-R.I.) disagreed. "I think the plan is the best possible one," he said, "because it recognizes that it's not a military struggle, but also a political struggle." The fight, he said, is "their fight" — meaning regional actors — and the plan has "great potential to work," given its emphasis on bolstering regional forces to put the Islamic State on the defensive and then to eradicate it.

"It is our fight," Graham replied. "It is not just their fight. This is a radical Islamic army that is pushing the theory of a master religion, not a master race like the Nazis. ... It's about protecting millions of people throughout the world. ... They're intending to come here. So I will not let this president suggest to the American people we can outsource our security and this is not about our safety."

"Our strategy will fail yet again," he said. "This president needs to rise to the occasion before we all get killed here at home." (There is no consensus among intelligence officials about the extent of the threat posed by Islamic State to the United States.) An NBC News/Wall Street Journal/Annenberg poll whose results were disclosed on NBC's "Meet the Press" on Sunday suggests that the American public agrees with Graham's skepticism. Sixty-eight percent think that the president's plan is unlikely to succeed.

"This is the last best chance" to stop them, Graham argued. "They will open the gates of Hell to spill out on the world. This is not a Sunni-versus-Sunni problem. This is ISIL against mankind."