Trump violated his oath of office

In what is perhaps the gravest accusation of presidential misconduct in a scandal-ridden four months, news outlets have reported that President Trump disclosed highly classified information to Russian government officials during their visit to the Oval Office last week. These are among the most serious charges ever made against a sitting president, though there is much we do not yet know. As additional information emerges, there are important points to keep in mind.

The reporting so far indicates that Mr. Trump did not violate any criminal laws concerning the disclosure of classified material. The president's ability to classify national security information flows from his constitutional powers as commander in chief. That means, in short, that he gets to determine what is classified in the first place and he may - even on a whim - lawfully declassify it or share it with whomever he sees fit. Even where the president's conduct does potentially involve violating the law - as with allegations that he obstructed justice by asking FBI Director James Comey to drop an investigation - the preliminary question is still political and not legal: the president must be impeached before he can be indicted.

The question of criminality, however, is by no means the only issue here. Mr. Trump is reported to have disclosed national security information of profound consequence: that relating to the sources of intelligence and methods of its collection. "Sources and methods," as it's known in the intelligence community, is especially crucial because it relates not only to the substance of intelligence, but also to the manner in which it was obtained. When this kind of information is revealed, the nation may no longer be able to use this method of collection in the future, with long-term security consequences.

It's important to understand that information related to sources and methods is handled with the same degree of care as actual sources and methods. That is for good reason. For example, imagine Bad Guy A and Bad Guy B discuss a terrorist plot over a single channel that they think is secure. If someone revealed that the government knew about the plot, and the bad guys learned that, they would also be able to deduce that the government had intercepted the communication channel and they would not use it to discuss the plot again. This is the kind of information Mr. Trump is accused of revealing to Russia.

This episode is especially worrisome because Mr. Trump did not just jeopardize the United States' intelligence sources, but those of another country - in this case, reports say, Israel. Intelligence-sharing partnerships are critical to American security interests, in particular in the coalition fight against the Islamic State. The American intelligence community and the military depend on a network of such partnerships with countries around the world.

Breaching the trust of a foreign partner in this way could substantially harm that relationship, and could undermine the confidence of other foreign governments in the United States' ability to safeguard their secrets. Before Mr. Trump's inauguration, some news outlets reported that foreign intelligence officials were concerned that the Trump administration could not be trusted with shared intelligence. To the extent foreign partners were already worried, their worst fears are now confirmed.

Inevitably, some Republicans will now point to any number of remarks by Democrats minimizing the significance or severity of disclosing classified information; some Democrats will do the same with previous Republican statements underscoring the importance of protecting classified information. It's true: There are plenty of examples of partisan hypocrisy and faux outrage regarding the other party's handling of classified material. But this is a distraction and should be ignored. We need to remain focused on the rationale for Mr. Trump sharing such sensitive information with the Russians, the manner in which he did so, and the possible consequences to American security relationships.

How our political system absorbs this news will depend a lot on why Mr. Trump chose to disclose this information to the Russians, particularly in light of reports that the compromised source may have been valuable in understanding Russian movements in Syria. If Mr. Trump believed this disclosure served a national security purpose, he must clearly articulate his rationale to the American people. So far, he has written on Twitter that he wanted to share with Russia "facts pertaining to terrorism and airline safety" for what he described as "humanitarian reasons." Lt. Gen. H. R. McMaster, Mr. Trump's national security adviser, has defended the president's actions as "appropriate."

These claims, however, are belied by the response of Mr. Trump's own national security team, which immediately recognized the gravity of the breach and took steps to mitigate the damage. We may have to confront the consequences of having a president with such exceptionally poor strategic judgment that National Security Council officials have to protect security interests from the president himself.

The alternative is far worse. The implication in the Washington Post article that broke the news is that Mr. Trump impulsively shared the information to brag about his "great intel." If this is indeed the case and the president behaved so recklessly with information of this nature, he may well be in breach of his oath of office.

When he was inaugurated, President Trump swore to "faithfully execute the office of president of the United States" and to "preserve, protect and defend the Constitution" to the best of his ability. Carelessly giving away classified material to a foreign adversary does not constitute a faithful execution of the office of president. And violating the oath of office does not require violating a criminal statute. If the president tweeted out the nuclear codes or the identities of covert intelligence officers, he would not violate any criminal law - just as he hasn't here - yet we would all understand this degree of negligence to be a gross violation of his oath.

Congress has alleged oath violations all three times it has passed or seriously contemplated articles of impeachment against presidents: against Andrew Johnson, Richard M. Nixon and Bill Clinton. Those charges all involved allegations of crime or breaches of statutory obligations - a precedent which may hold if reports regarding Mr. Trump's interference into an FBI investigation prove true. But where the conduct involves giving secret information to a foreign power, there is no reason that Congress couldn't consider the grotesque violation of the president's oath as a stand-alone basis for impeachment - a high crime or misdemeanor in and of itself.

The writer is a fellow at the Brookings Institution