As news broke that an Iranian drone came within 100 feet of a U.S. Navy F/A-18 landing on the USS Nimitz in the Persian Gulf, four analysts in Washington, D.C., reiterated their call to remove American forces from the region.

What's at stake for the U.S. being involved in a conflict that grows more complicated by the day? Everything, said former U.S. State Department official Matthew Hoh and former CIA counterterrorism analyst John Kiriakou.

Hoh and Kiriakou were accompanied by legal analyst Christie Edwards, and author and activist David Swanson.

"We are on the brink with a war with Russia," Hoh told an audience at a National Press Club event Tuesday.

Hoh resigned as the senior civilian representative in Zabul Province, Afghanistan, in 2009, making him the first known U.S. official to resign in protest of America's war in Afghanistan. A former U.S. Marine Corps captain, he had previously served two tours in Iraq.

He said the involvement of U.S. and Russian warplanes over Syria -- still a sovereign state -- is a clear violation of international laws.

And as each country continues to bait the other -- mainly in the Baltics and Ukraine -- the basis for involvement in Syria becomes even more misconstrued, Hoh said.

To further Hoh's point, Edwards, a legal analyst with the American Society of International Law and chair of the Lieber Society on the law of armed conflict, said Russia and the U.S. make contradictory claims for their presence in Syria.

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Edwards used the F/A-18E Super Hornet shootdown of a Syrian Su-22 in June after the Soviet-era fighter-bomber dropped munitions near U.S.-backed Syrian Democratic Forces fighters as an example.

"The U.S. claims that it acted in collected self-defense of coalition forces because the Syrian plane was bombing the SDF," Edwards said. "Russia, however, says the plane was providing air cover for Syrian ground forces fighting ISIS, so the U.S. action here violated Syria's sovereignty and international law and thus constituted military aggression against the Syrian government."

It doesn't help that Congress has not approved a new authorization of military force, or AUMF, in the region, she said. The Pentagon has been operating under the 2001 AUMF.

"Article 51 [of the United Nations Charter] does allow for collective self-defense of states but not necessarily non-state armed groups like the SDF. To be clear, the U.S. has not claimed that the SDF is a de facto organ of the United States -- it's providing some support, but it's not claiming it's a de facto organ under its control," Edwards said.

She also argued there is leeway that the U.S. can use "proportionate force" to defend members of the coalition and coalition non-state armed groups against ISIS, "if defeating ISIS was its sole mission."

The legal analyst said the waters have been muddied by U.S. officials such as U.N. Ambassador Nikki Haley and Secretary of State Rex Tillerson, who have repeatedly indicated a regime change in Syria, saying that Syrian President Bashar al-Assad is not the solution.

"The fact that there could be some mixed motives for both fighting ISIS, which is a strategic objective of the United States, and possible regime change -- the mixing of these motives compromise the legal basis for military operations that have occurred and may occur here in the future," Edwards said.

Recently, Air Force Brig. Gen. Charles Corcoran, commander of the 380th Air Expeditionary Wing, confirmed to Military.com that American pilots made the call to shoot down aircraft over Syria on three separate missions, including the Su-22 shootdown. He said the acts were all within the parameters of the rules of engagement.

"We're here to fight ISIS, but we're going to protect our forces from Syrian pro-regime entities," Corcoran told Military.com during a recent trip to the Middle East.

The general, however, did raise another point: Such calls may happen with more frequency as ISIS continues to lose ground in Syria, where a civil war has raged since 2011, and the U.S. finds itself operating in airspace increasingly congested by forces loyal to Assad and backed by Russia.

During an interview in his office, Corcoran said, "We're here to fight ISIS" but pointed to a map of Syria and Iraq outlining areas controlled by the Islamic State in red.

"It's pretty clear that at some point the 'red' is going to go away," he said, "and we're going to have state-on-state" forces fighting. "ISIS is a sideshow ... but what happens when the [other] two meet? Strategically, when ISIS goes away, that's the real issue."

Thus far, the U.S. has spent $14.3 billion in operations related to ISIS since kinetic strikes began on Aug. 8, 2014, according to the Defense Department.

Kiriakou, who served in the CIA from 1990 to 2004 and identifies himself as a CIA whistleblower, on Tuesday said, "The only way to save that country from becoming a failed state or an ISIS state is to sit at the table with all of the stakeholders, including the Syrians, the Russians -- and, whether we like it or not, the Iranians."

"We have to accept the fact that al-Assad is not going anywhere, nor should he," he said. "His is the internationally recognized government of Syria -- and that is no matter what [U.S. President Donald] Trump nor [former President Barack] Obama have said.

"We should sit across the table from Bashar al-Assad," Kiriakou said.

The former CIA analyst said the Russians have been invited by Syria to be there, while the U.S. has not.

But Swanson disagreed with the alleged legality of Russia's invite.

"Can an exiled dictator create legality by inviting other nations to attack his country? No, these are nonsense arguments for war," said Swanson, the director of WorldBeyondWar.org.

He added there are no legal statutes that say, "War is OK if a dictator asks you to help with it."

"The U.S. is committing a crime in Syria. So is Russia," Swanson said.

-- Oriana Pawlyk can be reached at oriana.pawlyk@military.com. Follow her on Twitter at @Oriana0214.