The Washington Post reported Monday that President Donald Trump had revealed classified information about the Islamic State to Russian Foreign Minister Sergei Lavrov and Russian ambassador to the United States, Sergy Kislyak, in a meeting at the White House last week.

The information, according to the Washington Post, concerned information about an ISIS plot to bomb airplanes using laptops. A senior U.S. official who asked not to be identified told the Associated Press the classified information had been shared with the president by an ally, violating the confidentiality of an intelligence-sharing agreement with that country.

The national security advisor, H.R. McMaster, and Secretary of State Rex Tillerson both said the president did not disclose intelligence “sources” or “methods” during the exchange, and on Tuesday, the president tweeted that he had the authority as president to share "facts pertaining to terrorism" and airline safety with Russia.

A statement from Deputy National Security Adviser Dina Powell read in part: "This story is false. The president only discussed the common threats that both countries faced."

According to The Post, Trump shared information that falls under a level of classified information known as “code word.”

Here’s a look at the levels of classification and what sharing it means.

What is classification?

Information is considered classified if "the national defense has required that certain information be maintained in confidence in order to protect our citizens, our democratic institutions, our homeland security, and our interactions with foreign nations".

Once it is classified, the sharing of that material could lead to prosecution.

What do the different levels of classification mean?

There are three levels of classification of U.S. intelligence material.

• Confidential – That applies to information which could "cause damage to the national security.”

• Secret – Secret classification is for information which could "reasonably ... be expected to cause serious damage".

• Top secret – Top secret information is information the government believes could "reasonably ... be expected to cause exceptionally grave damage to the national security."

What is code-word information?

Code-word information goes beyond the top secret clearance. It refers to the most classified information the government obtains, and it is protected with extremely limited access and unique security protocols.
It is administered by the CIA, and only people with the code-word access to the information may see it. According to the Washington Post story, what the president discussed with the Russians was under a code word.

Can the president share classified information? Is it against the law?

The president has the absolute right to distribute classified information. It is not against the law for him to share it.

Steven Aftergood, a government secrecy specialist with the Federation of American Scientists, told the Washington Post, "It is an expression of presidential authority, and that means that the president and his designees decide what is classified, and they have the essentially unlimited authority to declassify at will.

"The president defines the terms of the security clearance system and the parameters that determine who may be given access to classified information."

What would happen if anyone else shared confidential information?

They could be prosecuted under espionage laws. They would surely lose their security clearance.

What happens going forward?

European security official speaking with the AP said the move could have an effect on the trust between the U.S. and intelligence sharing partners. "It wouldn't likely stop partners from sharing life-saving intelligence with the Americans, but it could impact the trust that has been built, particularly if sharing such information exposes specific intelligence gathering methods," said the official, who spoke on condition of anonymity because the person was not authorized to speak about such intelligence sharing.