Asked recently by CNN what the United States needs most to fight ISIS on the Internet, James Glassman former under secretary of state for Public Diplomacy under President George W. Bush answered, “A commitment to the war of ideas.”   Fighting the terrorists on the battlefields in Iraq and Syria will not be enough. We need to engage in the ideological war, “just as we did during the battle with Communism.”

On the international scene, the first to boldly advocate this approach was British Prime Minister David Cameron. In remarks to the United Nations on Oct. 3. Cameron called for “defeating the ideology of extremism that is the root cause of this terrorism — so that we win the battle of ideas, not just the battle of military might.”

Glassman speaks with authority on the subject of fighting violent extremism. It was during his tenure at the State Department that the Center for Strategic Counterterrorism Communication was first established, which today takes the lead for the U.S. government on fighting ISIS propaganda and recruitment on the web. It is currently the best weapon we have, but it should not be the only one.

How to we fight this battle? With a two pronged approach, suggests Glassman. One the one hand, says Glassman, we do it by persuading returning foreign fighters to be interviewed and broadcast about their experiences with Islamist extremism, which many find to be a much different reality, more repressive and far more violent, than anything they had been led to believe online. Both the U.S. and European governments are currently grappling with how to deal with returning ISIS fighters.  The effectiveness of testimonials by disaffected fighters, however, has to be measured against the homeland security threat presented by returning foreign fighters to their communities.

Secondly, we need a forceful defense of Western principles based on freedom, justice, peace, tolerance– the principles indeed embraced by most of the world at this point. These universal principles, on which the United States itself was founded, stood up well in the battle against Communism, and would do so again in this battle if openly and forcefully embraced.

Unfortunately, under President Obama, the U.S. has been disarming itself in more ways than one. At the Pentagon, the Office of Strategic Communication has been shut down, and at Voice of America, the leadership bristles at the idea of promoting American values and policies. From the White House, Americans and the world are constantly reminded that the United States “has plenty of problems within its own borders,” as Obama relentlessly stated at the United Nations.  Not even during his U.N. speech, preparing for military action against ISIS, was the president able to refrain from a dig at his own country, suggesting a moral equivalence between the police shooting in Ferguson, Mo., and the massacres of innocent Christians and Muslims committed by ISIS.

The foundational ideas of Western civilization matter today as much as ever. But you have to believe in them to fill the vaccuum of confidence that has developed within our own political culture.