Top-secret codeword information derived from an ally is even more sensitive.

To a remarkable degree, the United States relies on liaison relationships with other powers with whom it shares information. If Trump has indeed compromised a source of information, it is not merely a betrayal of an ally’s trust: It is an act that will jeopardize a whole range of relationships. After all, the Director of Central Intelligence cannot very well say, “Don’t worry, we won’t share that with the president.” So now everybody—even our closest allies like the United Kingdom—would be well-advised to be careful with what they share with us. That is a potential intelligence debacle for us, but the danger goes beyond that. If any foreign government harbored lingering illusions about the administration’s ability to protect any information, including sensitive but non-intelligence matters like future foreign-policy initiatives or military deployments, they no longer do. They will be even more apprehensive about sharing sensitive information of any kind because…

He gave it to the Russians. In the Oval Office. In a fit of braggadocio.