The threat from terrorism is "nowhere near as dire as warmongers make it out to be, but it is much greater than it has to be," Daniel Larison argues:
It seems to me that non-interventionists and realists make blowback arguments to focus on the consequences of current policy, and to point out the flaw in a national security and warfare state that actively makes America less secure by creating enemies where none should exist and provoking attacks that need not happen. It is also a rhetorical move to appeal to public concerns about security without endorsing standard authoritarian and jingoist responses to threats. I can’t speak for anyone else, but what non-interventionists and realists should be trying to do is to channel the public’s appropriate moral outrage over terrorist atrocities towards reforming the policies that create these unintended, avoidable consequences. To that end, there doesn’t need to be any exaggeration of the nature of the threat or the power of jihadism, but there should be a steady stream of arguments that the threat can be significantly reduced or possibly eliminated by reforming U.S. policies so that they actually minimize the risks to the nation rather than generate new dangers. The threat from terrorism isn’t all that great, but it could be greatly reduced. All that it will cost us is our undesirable pursuit of hegemony.
One doesn't hear more politicians arguing that the terrorism threat is overblown partly because it's the sort of thing that could destroy one's career if there is even one successful terrorist attack, or even a particularly frightening attack that is averted. It's the sort of risk no one takes in politics, because being right has no upside for the politician, and being wrong has a huge downside. The blowback argument is as direct a repudiation of War on Terror adventurism as any major figure is likely to make.