The Senate is launching a debate on its annual defense authorization bill this week amid the specter of war with Iran.

It is not clear to what extent possible U.S. military strikes on Iran will play a role in debate on the $750 billion measure or, for that matter, in a separate vote this week on blocking U.S. arms sales to Saudi Arabia, Iran’s arch foe.

[Iran escalations bring war powers debates back to the Capitol]

But the talk about Iran in Congress, by turns belligerent or anxious, swelled this week as tensions spiked in the Middle East.

Iran appears to be responding more aggressively to President Donald Trump’s unilateral abrogation last year of a 2015 deal under which Iran agreed to suspend activities that could lead to a nuclear-arms capability in exchange for a relaxation of sanctions.

More specifically, the U.S. military accused Iranian maritime forces of detonating mines last week to damage two commercial oil tankers in the Gulf of Oman. Iran then said Monday it would begin to produce uranium at a higher level of enrichment than allowed under the 2015 deal, moving it potentially closer to materials that could be used for atomic bombs. The United States announced that same day it would send another 1,000 military personnel to the region, on top of an additional 1,500 sent over in May.

All of this has members of Congress bracing for U.S. airstrikes on Iran and an inevitable response by Tehran.

“We are talking about a military response on the table that would cripple their ability to do this by attacking the naval force that has been the military force against our vessels. And we’re talking about destroying their ability to refine oil,” said South Carolina Republican Sen. Lindsey Graham, a leading voice among congressional hawks, in an exchange with reporters Tuesday.

Asked what form such an attack would take, Graham said: “I’m talking about blowing it up.”

Hawks circle

Likewise, Majority Leader Mitch McConnell began the Senate’s day Tuesday with a floor speech on Iran.

“I would urge every one of my colleagues to keep these deadly serious developments at the top of our minds as we tend to our business in the days ahead,” McConnell said. “The president has said he does not seek conflict with Iran. Neither does the Senate. Nevertheless, the risk of a conflict is real.”

Meanwhile, Oklahoma Republican James M. Inhofe, chairman of the Senate Armed Services Committee, told reporters he was “not advocating” a strike against Iran, but nor did he oppose one.

“We are a country that’s not going to let someone push us around, and we will act accordingly,” Inhofe said.

Louisiana Republican John Kennedy, for his part, told reporters he thinks Iran is “a cancer on the world.”

Arkansas Republican Tom Cotton, a member of Armed Services, has called in broadcast interviews for a military strike on Iran.

The rising bellicosity came on the same day Trump announced Patrick Shanahan, his acting Defense secretary, would be replaced in the acting position by Army Secretary Mark Esper.

The shakeup at the top of the U.S. military, occurring against the backdrop of the tensions with Iran and other nations, has rattled some lawmakers.

Rep. Mac Thornberry of Texas, the top Republican on the House Armed Services Committee, issued a statement Tuesday showing he would not look favorably on another acting Defense secretary waiting months without being nominated.

Lack of a permanent secretary “encourages our enemies and unsettles our allies,” Thornberry said.

Amendments teed up

The Senate could debate in the coming days an amendment to the defense authorization bill, or NDAA, that would require congressional approval before any U.S. military action is taken against Iran. Democrat Tom Udall of New Mexico and Rand Paul of Kentucky lead a bipartisan group that has sponsored such an amendment.

However, it is not clear McConnell would allow such a proposal to come up for a vote — or how many NDAA amendments in general will be debated.

A similar Udall amendment on Iran recently failed in the Senate Foreign Relations Committee, 9-13, a likely sign of its slim odds on the floor.

Amendments taking a harder line on Iran could be considered. No proposals endorsing a strike have surfaced. But Texas Republican Ted Cruz has a couple of amendments to impose additional sanctions on Iran, including on its civilian nuclear sector.

The House, meanwhile, does not appear poised to debate authorization for an Iran strike — at least not this week while it considers the Defense money legislation as part of a four-bill package. The Rules Committee has not made in order an amendment to that bill by Connecticut Democrat Jim Himes limiting the kinds of U.S. military action the president could take against Iran without Hill approval.

However, the Iran issue could very well come up in the House starting the week of July 8, when the chamber plans to begin floor debate on its own version of the NDAA.

If the House takes up an Iran war authorization amendment, it may come from California Democrat Ro Khanna. He had filed such an amendment for consideration when the House Armed Services Committee marked up its bill earlier this month, but Khanna withdrew it and said he would seek to improve it ahead of the floor debate.