(CNN) President Donald Trump's decision to kill a top Iranian general and risk a war without consulting lawmakers has prompted Republican griping, with even close Trump allies going on the record to rein in the President's power to escalate things further.

That's in part because, a full week after the airstrike that killed Gen. Qasem Soleimani, the White House has yet to offer a clear, consistent articulation of what "imminent" attack the US was trying to avoid -- and, in fact, top administration officials are offering conflicting justifications, raising key constitutional questions.

While Republicans have largely fallen in line on the question of whether Trump should be allowed to pressure a foreign country -- Ukraine -- to undermine his political rival , they are exerting a few flashes of independence from the White House when it comes to attacking Iran.

The President has made specific allegations about the necessity of killing Soleimani. His top aides have remained much more oblique, making it seem as if they are trying to cloud the record without contradicting their boss.

Of course, ignoring Congress and fighting over policy and funding with lawmakers has been a constant of Trump's presidency, even during his first two years, when Republicans controlled both the House and the Senate.

Those fights intensified when Democrats took control of the House a year ago, leading to a record-setting government shutdown in early 2019. Then, when Trump blew off questions about his pressure on Ukraine to investigate his political rivals and tried to squash a congressional investigation, House Democrats impeached him for it.

Trump's decision to kill an Iranian general and tempt war without consulting Congress was of a different order, and created a national security crisis that puts American lives at risk. And Congress, like the public, has been kept in the dark on some of the most important intelligence.

It's an important question because, if there was no imminent threat of danger to Americans, the killing veers from anti-terror operation to political assassination. The Constitution, which gives Congress the power to declare war, did not envision that sort of power.

Embassies targeted

Expanding on an already broad list of justifications for the killing, Trump said at a rally with supporters in Ohio on Thursday that Soleimani had been plotting to blow up the US Embassy in Iraq, along with other diplomatic locations.

"Soleimani was actively planning new attacks, and he was looking very seriously at our embassies, and not just the embassy in Baghdad," Trump said, adding, "but we stopped him, and we stopped him quickly, and we stopped him cold."

He added in a Fox News interview on Friday that four embassies had been targeted. But Trump is the only US official to make that specific allegation in that way. Others, including Secretary of State Mike Pompeo and Chairman of the Joint Chiefs Mark Milley, have been much more vague, promising they had the goods to justify "imminent" threat, but failing to say publicly what the intelligence was.

Lawmakers, however, said there was no mention of embassy targeting in their briefings this week.

"I listened very carefully. I definitely would have known if anyone said that. That is news to me," Democratic Sen. Tim Kaine of Virginia told CNN's Ted Barrett.

A vague target 'in the region'

Pompeo, a former CIA director, had previously said that the exact timing or target of an attack was unknown.

"It was going to be against the United States of America, likely in the region. We can't say much more than that, but the American people should know there was an attack. It was in the planning stages, but we had seen Qasem Soleimani be able to deliver on this kind of plan before," he said in a Fox News appearance on Thursday.

Interviewer Laura Ingraham, on Friday, specifically asked if Soleimani wanted to blow up the US Embassy in Iraq. Pompeo didn't say yes, but mentioned previous protests that jeopardized the US Embassy.

"It was his forces that penetrated our embassy just a handful of days before that -- Kata'ib Hezbollah warriors orchestrated and directed by Qasem Soleimani himself. I don't think there's any doubt that Soleimani had intentions not only to take action against our forces, our diplomats in Iraq, but in other countries around the region and world as well."

Later Friday, Pompeo was pressed about the discrepancies.

The White House briefing room exchange, in which he maintains the "imminent" language and insists on the lack of specificity, is key. Here's how it reads:

Q: Can you clarify? Did you have specific information about an imminent threat, and did it have anything to do with our embassies?

POMPEO: We had specific information on an imminent threat, and those threats included attacks on US embassies. Period. Full stop.

Q: So you were mistaken when you said you didn't know precisely when and you didn't know precisely where?

POMPEO: Nope. Completely true. Those are completely consistent thoughts. I don't know exactly which minute. We don't know exactly which day it would've been executed. But it was very clear: Qasem Soleimani himself was plotting a broad, large-scale attack against American interests. And those attacks were imminent.

Q: Against an embassy?

POMPEO: Against American facilities, including American embassies, military bases. American facilities throughout the region.

Why Congress wasn't briefed

Vice President Mike Pence said lawmakers couldn't be trusted with the most sensitive information.

"Some of that has to do with what's called sources and methods," Pence said Thursday on NBC's "Today" show. "Some of the most compelling evidence that Qasem Soleimani was preparing an imminent attack against American forces and American personnel also represents some of the most sensitive intelligence that we have -- it could compromise those sources and methods."

Except that's not generally the way it's supposed to work. Congress is supposed to be in the loop. And not every member of Congress. Rather, just eight lawmakers -- the so-called Gang of 8 -- representing the top two lawmakers from each party in the House and Senate and four top leaders from the intelligence committees. The Trump administration has ignored this bipartisan notification with previous operations, too.

But the larger question for Congress is focused on the future, particularly if the situation reescalates. The last time Congress authorized the use of military force was in 2003, when it voted to let President George W. Bush invade Iraq. Actions against terror groups are conducted under the 2001 vote taken after the 9/11 terror attacks. Democrats, along with a few Republicans, voted in the House to restrict Trump's ability to act against Iran.

Certainly there are competing interests -- justifying the killing of an individual by the US government vs. protecting methods and sources of intelligence gathering. But Democratic Sen. Bob Menendez of New Jersey said he had attended the intelligence briefing for senators and left without any clarity.

"I think this is a case where one ultimately molds the intelligence that exist to fit what you want to do," Menendez said on MSNBC.

On Thursday, Republican Rep. Matt Gaetz of Florida, a close Trump ally, voted in favor of a Democratic-written war powers resolution , saying it was because the "Trump movement is an anti-war movement."

"I think the President needs to see his allies animating his true beliefs and instincts," Gaetz said. "I think that it's actually harmful to the President if all of the Republicans look like the pro-war party."

What happens next?

Sen. Mike Lee, a Utah Republican, erupted after a briefing by administration national security officials specifically over this question of separation of powers.

"It was, instead, about the possibility of future military action against Iran," he told NPR . "And it was on that topic that they refused to make any commitment about when, whether and under what circumstances it would be necessary for the President, or the executive branch of government, to come to Congress seeking authorization for the use of military force."

JUST WATCHED Sen. Lee on Iran briefing: Worst briefing I've seen on a military issue Replay More Videos ... MUST WATCH Sen. Lee on Iran briefing: Worst briefing I've seen on a military issue 01:48

But Lee and other Republicans raising the alarm about war powers are still in the minority in their party. Even for some Republicans who want to have a debate on war powers, now is not the time, because it could damage Trump.

"I absolutely think we need to have an honest debate on the war powers act," said Rep. Austin Scott, a Georgia Republican. "But it does not need to be specific to one country and it does not need to be done in the manner in which it was done." He said the debate should occur "when it's not seen as an attack against the President."