Former Defense Secretary Chuck Hagel on Thursday sharply criticized tough talk on Iran from senior Trump administration officials determined to ouster regime-backed forces from Syria.

“The U.S. doesn't even control half of Syria. You've got 2,000 [U.S.] troops up in the northeast corner. I mean, come on, you're not going to drive Iranians out of Syria with 2,000 American troops,” Hagel said in an interview with Defense One. “It’s complete folly to think you’re going to threaten the Syrians or the Russians or the Iranians into anything.

“The Iranians live there,” he continued. “The U.S. doesn’t live in the Middle East. Unless you’re going to somehow eliminate the geopolitical realities of that—well, good luck Mr. Bolton. There is no other way around this, you’re going to have to find some resolution based on the common interests of those countries.”

Hagel’s criticism comes at a moment of intense scrutiny of the Trump administration’s strategy to box in Tehran, an objective that officials have made a cornerstone of the president’s foreign policy in the region. National Security Advisor John Bolton last week ignited speculation that the Trump administration may be beginning to lay out legal justifications for military strikes against Iranian or Iran-backed fighters when he told reporters at the United Nations General Assembly in New York that the U.S. would maintain its presence in Syria as long as Iran-backed forces were present in the country — an apparent policy shift that appeared to reverse years of Pentagon assertions that U.S. forces are only there to fight ISIS.

"This is not the Obama administration, would be my message to Iran and anybody else," Bolton told reporters at the White House later on Thursday while rolling out the Trump administration's new counterterrorism strategy, which makes Iran a focus.

Hagel scoffed at the notion that the presence of 2,000 U.S. troops in Syria would be sufficient to ensure the departure of the thousands of Iran-backed fighters and proxy militia leaders operating in support of Syrian President Bashar al-Assad’s regime.

“You tell me what the foreign policy objective is to using 2,000 American troops stationed in Syria and then I'll give you an answer. I don't know what our foreign policy objective is in the Middle East or almost anywhere else," Hagel said.

“How do you accomplish some stability in Syria?...You're not going to do that without the Russians, without the Iranians, without the other players in the country, in the region.”

So what is U.S. policy in the Middle East?

If you ask Hagel — one of the Senate’s top Republican foreign policy leaders from 1997 to 2009 and later defense secretary for President Barack Obama — there doesn’t appear to be one.

Hagel argued the administration's recent decision to remove four Patriot missile batteries from key Gulf allies, did not square with the Trump administration’s tough-on-Iran rhetoric..

If constraining Iranian influence is the goal, Hagel said, “how do you think you’re going to have more leverage against Iran by pulling Patriot batteries out of countries, and not paying attention to some of these areas, but [instead] just making these bullying speeches about, ‘We’re gonna sanction you’?”

“This is my point about the confusion. Where are we? What is our policy?”

So far, Trump’s overt pressure on Iran has taken place primarily in the diplomatic and financial sphere.

In May, President Donald Trump withdrew from the so-called Iran nuclear deal, which traded sanctions relief for curbs on Iran’s nuclear weapons development program. And on Wednesday, Secretary of State Mike Pompeo blamed Iran for threats on American personnel in Iraq and withdrew from an Eisenhower-era “treaty of amity” with Tehran that has been used by both countries as the basis for resolving claims in the International Court of Justice.

The U.S. military long has claimed that Congress’ authorization to fight al-Qaeda and its affiliates gives it permission to fight ISIS in Syria. But Congress has passed no legal authorization for U.S.military forces to directly engage with Iranian or Iranian-backed groups. Some national security law experts suggest that the Pentagon’s new internal interpretation of its legal authority to carry out strikes in the context of “collective self defense” could theoretically be used to justify a strike on Iran or Iran-backed forces.

Gen. Joseph Votel, the head of U.S. Central Command, told reporters on Thursday that the military’s presence in Syria has “an impact” on Iranian activities but that CENTCOM had not been given a new mission.

“I don’t think we’re seeking to go to war with Iran,” he said. “I think the president has made it clear that Iran needs to cease its destabilizing behavior and policies that spread violence and human misery throughout the Middle East.”

But as officials have begun to hint at a longer-term U.S. presence in Syria, uncertainty about the military’s role has led to rising questions from lawmakers about the broader strategic mission in Syria.

“The military can’t fix problems alone,” Hagel said. “The military has to be used as a force to help implement and project and protect a strategic foreign policy objective.”