WASHINGTON 

Numerous US senators pressed Under Secretary of Defense for Policy Elbridge Colby on Tuesday on ongoing military operations in Iran as he testified on national defense strategy.

Senate Armed Services Committee chairman Sen. Jack Reed said the military operations unfolding in the Middle East are "completely contrary" to the strategy that the Pentagon published about 39 days earlier.

Colby pushed back, saying: "I completely reject that characterization. Sir, if you’d look in the strategy, it details specifically not only the threat posed by Iran and ensuring that the president has the options to act against Iran. It also explicitly and repeatedly details that the strategy will provide the ability…to do exactly this kind of operation.”

Colby said Israel and the Gulf allies “are really leaning in” by helping with military operations in Iran.

Since Saturday morning, Israel and the US have carried out strikes on Iran, killing Supreme Leader Ayatollah Ali Khamenei and many top security officials.

Iran in response launched drone and missile attacks on Israel and US military assets in the region, prompting many Gulf states to close their airspace.

Reed accused Trump of having "moved the goal posts constantly" and asked Colby to explain the objectives of the operation.

"Once again, the objectives of the military campaign, which have been directed by the president...are focused on addressing the ability of the Islamic Republic to project military power against of course us, our bases, our forces, etcetera, as well as our allies and partners in the region and beyond, and that's primarily the missile forces of the Islamic Republic," Colby said.

"I do think those are scoped and reasonable objectives that can be attained."

"Why was the first objective in the campaign the attack and death of Khamenei and key leaders of the regime?” Reed said.

Trump “sets our agenda and he directed these military goals,” Colby replied.

Colby's remarks came after Secretary of State Marco Rubio said the US knew that there was going to be an “Israeli action” against Iran.

"We knew that that would precipitate an attack against American forces, and we knew that if we didn’t preemptively go after them before they launched those attacks, we would suffer higher casualties,” Rubio told reporters on the Capitol Hill.

Trump on Tuesday denied that Israel dragged the US into war with Iran.

"No, I might have forced their hands. You see, we were having negotiations with these lunatics, and it was my opinion that they were going to attack first,” he told reporters at the White House.

Sen. Angus King, for his part, called Rubio's statement "breathtaking."

“Have we now delegated the most solemn decision that can be made in our society, the decision to go to war, to another country? That’s the implication, the breathtaking implication of Secretary Rubio’s statement,” King said.

The senator said Rubio “inadvertently told the truth” that the war was driven by Israeli Prime Minister Benjamin Netanyahu.

“I agree with you that Secretary Rubio told the truth. I wouldn’t characterize his remarks,” Colby replied.

“I find it very disturbing that we're committing this nation to war based upon a decision by…a staunch ally, and I'm a supporter of Israel. But I don't think anybody should drive our decision to go to war,” King said.

Sen. Elizabeth Warren pressed Colby on how Trump’s “America First” approach aligns with Washington’s involvement alongside Israel in the war with Iran.

She also asked whether joint actions by Israel and the US constitute “interventionism.”

“I don’t think this is. No,” Colby replied, adding that interventionism is "a more, I would say, you know, kind of responsibility to protect or something."

"Really? And we didn't do this in order to try to protect Israel?" said Warren.

Colby said it was "one of the goals."

"So it is interventionism," Warren said.

“The Trump administration first says it’s going to be America First, then puts out a national defense strategy and then goes to war alongside Israel illegally, unconstitutionally,” she said.

“And that is now the policy of the Trump administration: say one thing in a campaign, write it down on paper, and then go do whatever the hell you want.”

Sen. Tim Kaine also characterized the US actions both in Venezuela and Iran as "interventionism."

"Is arresting (Venezuelan President Nicolas) Maduro and killing the Ayatollah, is that regime change?" he said.

Colby fell short of answering the question, saying: "I don't know. I think it's an interesting debate."

"You are uncomfortable having your own words read to you, and you're uncomfortable saying that the assassination of a leader and the arrest of a leader, you won't acknowledge that's regime change. I think that's very instructive to those listening," Kaine said.