Former Vice President Dick Cheney on Wednesday said it was time to get “back on offense” in the war on terrorism and delivered a blistering critique of President Barack Obama’s foreign policy, hours before Obama is expected to unveil his strategy for combating a militant group ascendant in the Middle East.

Cheney’s remarks came in a closely watched speech at the conservative American Enterprise Institute, a day before the 13th anniversary of the Sept. 11, 2001, terrorist attacks.

“As we work to defeat [the militant group] ISIS and prevent the establishment of a terrorist safe-haven in the heart of the Middle East, we must move globally to get back on offense in the war on terror,” Cheney said. Jabbing at previous Obama assessments of international stability, he continued, “This means, first recognizing and admitting the size and scope of the threat we face. Al Qaeda is not ‘diminished,’ nor is the ‘tide of war receding.’ Wishing doesn’t make it so. Our president must understand we are at war and that we must do what it takes, for as long as it takes, to win.”

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Obama has come under fire from Republicans—and some Democrats— who have wanted to see a faster and more forceful response to the Islamic State in Iraq and the Levant, which is often referred to as ISIL or ISIS. The group has claimed responsibility for the beheadings of two American journalists as well as numerous other attacks and killings, and Defense Secretary Chuck Hagel has warned that it could pose a direct threat to the United States. The administration has indicated it wants to “degrade” and “destroy” the group.

“We can hope for, and we should look for, signs of a forceful, bold, immediate strategy to defeat ISIS,” Cheney said of Obama’s Wednesday night address. “We can say already, however, that such a plan would mark an abrupt and dramatic departure from [Obama’s] record thus far.”

The former vice president said the rise of ISIL is one dynamic that makes “the situation today one of the most dangerous we have faced, certainly in my lifetime, and far more dangerous than the administration has been willing to admit.”

(WATCH: Previewing tonight's ISIL speech)

Cheney, who played a central role in the now-deeply unpopular decision to invade Iraq — a move many critics say fueled more militancy in the Middle East — is a highly controversial figure in many political circles. But on Wednesday he encountered a friendly audience peppered with Bush administration alumni such as former U.S. Attorney General Michael Mukasey and Bush speechwriter Marc Thiessen. Several attendees could be heard gleefully discussing a Wall Street Journal 0p-ed headlined, “Dick Cheney is Still Right.”

And Cheney himself signaled a sense of vindication, saying that Obama has referenced the security apparatus that, Cheney said, the previous administration put in place and has thus far successfully prevented terrorist attacks on U.S. soil. “Nice to hear, especially from someone who used to speak so disparagingly about the steps we took after 9/11,” he said.

But that “apparatus,” he said, is only effective if there’s a high level of “military preparedness,” something he said has receded under Obama.

“We are investing in defense as if the dangers of the world were all in quiet retreat,” Cheney said. “Of course, they’re not.”

He outlined a litany of international problems facing the United States, from Syria to Iran to Russia, and said allies and adversaries alike aren’t seeing a strong response from America.

Tehran, he said, is “not impressed,” while friends in the Middle East are asking, “What is President Obama doing?”

Obama ran for president on a platform that included ending the war in Iraq, and he has backed building international coalitions in the face of global problems —a rebuke to the unilateralism that sometimes characterized Bush-era policies. Obama’s administration, embracing the mantra “don’t do stupid stuff,” has at times refrained from overseas engagements that hawks in both parties pushed for, including earlier involvement in Syria.

“A policy of nonintervention can be just as dogmatic as its opposite,” Cheney warned.

The former vice president, who met with Capitol Hill Republicans on Tuesday, said he received a “great reception” —“they never treated me like that when I was vice president,” he quipped.

Asked about strains of isolationism in his own party, Cheney invoked 9/11, saying that he seeks to remind his “friends” that “these issues are very real, very imminent.”

Obama is slated to speak around 9 p.m. Wednesday.