The Iran War is now in its 20th week, and new records obtained by the NBC Chicago investigative team reveal there has been one American military death in the warzone for nearly each week since it started.

What’s more, data gathered by the Defense Department shows this is a more lethal war for U.S. service members than has been characterized by department leaders.

Now, top Chicago and Illinois legislators are demanding answers and changes.

After the deaths of three more servicemembers this week, President Donald Trump on Tuesday said he has a message for Iran.

“They will pay,” he said.

The president’s promise to avenge American war dead comes as he plans to be on hand for the dignified return of the most recent fatalities, as he has previously at Dover Air Force Base. But almost five months into the war, U.S. casualties continue to climb as attacks have intensified.

According to Pentagon data, 18 Americans have died during Operation Epic Fury, 10 of whom were killed during hostile action.

Government records show 447 service members have been wounded in action, with most of the casualties occurring in the first three months of the war.

“The president went forward and attacked Iran without consultation with our allies or with our NATO alliance. He did it on his own,” said Sen. Dick Durbin. “I’m sure he believed in his mind that if there was enough force there, they would be frightened into submission. It didn’t work.”

The NBC Chicago investigative team talked with the retiring Durbin and his Democratic Illinois colleague Sen. Tammy Duckworth, a Purple Heart Gulf War veteran, about a continuing war that is largely split along party lines.

“We did pass a War Powers Resolution out of the Senate in a bipartisan manner, and I think that we can pressure my Republican colleagues to step up again,” Duckworth said. “What we can do is we can cut off the funding. I actually have an amendment in this year’s defense budget that says no more money will be spent on prosecuting this war.”

We also spoke with long time Illinois congressman and Intelligence Committee member Mike Quigley, who is also a declared candidate for Chicago mayor.

“Just literally four or five Republicans are willing to say no more war, despite the fact that this is the president that campaigned on no new wars and that he would end inflation,” Quigley said. “The inflationary pressures are hitting home hard. Gas is over $4 a gallon in Chicago. The cost of everything from tomatoes to cars is going to do nothing but go up dramatically.”

And then the Northwest Side congressman dropped the Q word, harkening from Vietnam days a description that sends shivers through whole communities.

“It’s a quagmire now because we’ve already lost,” Quigley said bluntly.

During a Senate hearing on Tuesday Pentagon officials defended war spending, and asked for billions more, but admitted Iran’s arsenal is not exhausted.

“I acknowledge they still have capabilities, no doubt,” said Defense Secretary Pete Hegseth, who uses the title Secretary of War. “The amount of damage that we’ve done to them over the course of these series of operations has put them in the worst place they’ve ever been.”

Quigley blasted Hegeseth and the administraton’s characterization of Iran’s capabilities at this stage in the conflict.

“This is a president and an administration, when they get in the room with the truth a fight breaks out. I don’t have any faith in the numbers, the facts, the statistics that they’re alleging on anything that’s happening with this war,” he said.

Quigley, in his 10th year as a member of the House Permanent Select Committee on Intelligence, told NBC Chicago: “We hear the nation’s most important secrets. For the first time, and it’s been under Republican administrations, the first in that tenure…I don’t believe what we are being told.”

NBC 5 Investigates invited congressional Republicans in Illinois to respond to all of this and to do interviews about the ongoing Iran war. There are only three GOP members of Congress from Illinois.

One said he might be able to do an interview in the future and two others didn’t respond.