Every president in U.S. history has possessed some form of government or military leadership experience prior to assuming office. Donald Trump and Ben Carson have none.

Up until now, that fact has not mattered. Recent polling continues to show Carson and Trump comfortably leading the GOP pack. According to a Rasmussen survey on Friday, Trump leads the field with 27 percent support. Carson sits second at 20 percent.

Yet, in the wake of the Paris attacks, the contest “is shifting from a campaign for the presidency to a test for commander in chief,” according to Politico reporter Shane Goldmacher. Foreign policy experience was a “dirty word.” Now it is the key issue.

Trump and Carson’s credentials are coming into question as voters weigh whether foreign policy experience matters.

As Jeff Chidester, my colleague at the University of Virginia’s Miller Center, has shown, major international crises nearly always befall a president in the first year.

Examples abound: The Sept, 11, 2001, terrorist attacks; the Aristide coup in Haiti; Tiananmen Square. In fact, the trend stretches all the way back to the founders. Look up the XYZ Affair or the First Barbary War.

Friday’s events in Paris underscore this point. To most Americans, the threat of terrorism crossing the Atlantic looms far larger now than it did a week ago.

History also shows that handling these unforeseen disasters involves a steep learning curve, even for those with decorated military or governmental backgrounds.

The Miller Center has interviewed hundreds of these senior officials spanning six administrations as part of its Presidential Oral History Program. Excerpts from the George H.W. Bush and Bill Clinton transcripts are used throughout this piece to bring the difficulties of crisis management into greater relief.

President George H.W. Bush had a particularly impressive foreign affairs résumé when entering office. He was surrounded by a who’s who of the security establishment.

As then-Defense Secretary Dick Cheney observed, “We weren’t a bunch of amateurs. We’d been around there before.”

He went on: “We had a President who had been schooled in it for years. I’d been White House Chief of Staff. [Brent] Scowcroft was doing the NSC job for the second time. We used to joke he was going to have keep doing it until he got it right. [James] Baker had been Chief of Staff and Secretary of Treasury and now State. General [Colin] Powell’s background. This was a pretty experienced crew.”

Yet despite its collective experience, the Bush team faltered when facing its first major foreign policy test, in Panama.

Bush’s deputy national security adviser, Robert Gates, recalled, “The goal was basically just to get Noriega out of power and try to put a democratic government in Panama.”

Scowcroft claimed the roots went back to Bush’s time as vice president. When Noriega hijacked the elections, Bush “decided that, as soon as the opportunity arose, something was going to happen.”

His opportunity arrived shortly thereafter when a Panamanian national initiated a coup attempt. But failures abounded as the White House scrambled to respond. Information was incomplete.

“We were unable to pin down exactly what the plotters had in mind, exactly who they represented, exactly what they planned to do with Noriega,” Scowcroft said.

The team was ill-prepared. It lacked cohesion.

“We were disorganized, out of place,” Cheney added. “I’m up running around in Gettysburg. General Powell had just been sworn in; he’s the new chairman. I don’t know where the hell Baker was. We didn’t react well to it…we weren’t as good as we need to be.”

They wavered. No clear choice was made about America’s level of involvement. A major policy stumble ensued.

“The coup was unsuccessful. We did not act very decisively,” Scowcroft said. “This was our first crisis. We didn’t do particularly well in it.”

President Clinton, too, was unsuccessful in traversing the first crisis of his administration, this time in Somalia.

Once more the team was eminently qualified. Clinton’s first U.N. Ambassador, Madeleine Albright, had worked for the National Security Council under President Jimmy Carter. Secretary of State Warren Christopher was a veteran of the Carter and Nixon administrations. Powell stayed on as chairman of the Joint Chiefs. The list goes on.

But once more a first-class team stumbled.

There was no time to settle in. Deputy national security adviser Samuel Berger got a call from Scowcroft during the transition in which he stated, “I just wanted to let you know that we are going to send [27,000] troops into Somalia.”

But Scowcroft also indicated that peacekeepers would be out in two to three weeks. The incoming Clinton team had no great sense of urgency as a result. The matter was left largely to the military establishment.

“I do not believe the White House was involved or engaged to any great extent,” former deputy defense secretary William Perry said. “I think it was Les [Aspin] and Colin Powell, basically, managing the issue.”

Clear authority between the United States and the United Nations also was not established.

“We turned the operation over to the U.N., although our military was still there but not part of the U.N. We did not ‘blue-helmet’ our military,” Berger said.

Disaster followed. A helicopter was shot down. Eighteen Americans lost their lives. Horrible images followed of the bodies of slain soldiers being dragged through the streets of Mogadishu.

As National Security Council adviser Nancy Soderberg notes, the administration was “blind-sided.” This was Clinton’s “Bay of Pigs.”

Which brings us back to the question of whether experience matters. Two divergent arguments result from these historic moments.

You could say that even though the most experienced administrations stumble when handling their first crisis, it would be especially reckless to trust green candidates with such a critical responsibility. While the Bush team stumbled, things would probably be far worse under Carson or Trump.

Ohio Gov. John Kasich defended this view in the third GOP debate: “Folks, we have to wake up. We can’t elect somebody who doesn’t know how to do the job.”

But the opposite also may be true. Maybe Kasich is wrong. You could spin it the other way.

If Bush and Clinton were unprepared, then perhaps no amount of experience can ready a president for the first crisis. In that case, Trump and Carson’s unconventional résumés would not matter.

Of course, other variables come into play when selecting a commander in chief. For instance, the ability to adapt after early stumbles is a separate issue. But when it comes to initial experience, the answer is not definitive.

Contradictory statements made by Cheney about Panama attest to this.

He began, “It’s like anything else, if you’ve done it, you have a better feeling about how to do it.” But then he may have inadvertently doubled back when he added that, in “crisis management, the only way to learn it is to do it.”

Where GOP voters ultimately lean in this argument will be critical. It will have major implications on the prospects of the Republican front-runners and perhaps even the quality of crisis management we get from our 45th president.