This time, the stakes are too high to wait. Immunity should be granted as soon as Congress and prosecutors are persuaded that Mr. Flynn has information that will lead to a criminal case against one or more people at least as important to the alleged wrongdoing as Mr. Flynn may be. The overriding objective must be learning who if anyone in the United States collaborated with the Russians as well as who knew about it, what they knew and when they knew it.

This case is different from ordinary criminal investigations. Finding the truth is even more important than punishing the guilty, because it is critical to our national security and the future of our democracy.

It is also vitally important that decisions about whether to grant Mr. Flynn immunity, and all other decisions about the Trump-Russia investigation, be made only by people who are completely independent of anyone who could possibly be a subject or target of that investigation. This includes President Trump, who made Mr. Flynn his top national security adviser and, during the presidential campaign, openly encouraged the Russians to spy on his opponent and to reveal what they found.

Thank goodness Mr. Flynn’s campaign colleague, Attorney General Jeff Sessions, who also had contacts with the Russians that he was not truthful about, has recused himself from the investigations. President Trump’s appointees in the White House and in the Department of Justice should do the same. President Trump’s tweet on Friday morning only emphasizes the point. All of this is yet one more reason to do what we and many others have long urged, which is to appoint an independent special counsel to take over the executive branch’s investigation.

Congress — particularly the House of Representatives — has also compromised its independence by treating the Trump-Russia investigation as a partisan issue. The chairman of the House Intelligence Committee, Devin Nunes, has turned it into a farce by running over to the White House to give and receive information in the dark of night, and even to possibly publicly divulge classified information. He must also recuse himself for purposes of the immunity grant and the investigation as a whole.