WASHINGTON — Lost in the showdown between President Trump and James B. Comey, the former FBI director, that played out last week was a chilling threat to the United States. Comey testified that the Russians had not only intervened in last year’s election, but would try again.

“It’s not a Republican thing or Democratic thing — it really is an American thing,’’ Comey told the Senate Intelligence Committee. “They’re going to come for whatever party they choose to try and work on behalf of. And they’re not devoted to either, in my experience. They’re just about their own advantage. And they will be back.’’

What started out as a counterintelligence investigation to guard the United States against a hostile foreign power has morphed into a political scandal about what Trump did, what he said, and what he meant by it.

Lawmakers have focused mainly on the gripping conflict between the president and the FBI director he fired with cascading requests for documents, recordings, and hearings.

But from the headquarters of the National Security Agency to state capitals that have discovered that the Russians were inside their voter-registration systems, the worry is that attention will be diverted from figuring out how Russia disrupted American democracy last year and how to prevent it from happening again.

Russian hackers did not just breach Democratic e-mail accounts; according to Comey, they orchestrated a “massive effort’’ targeting hundreds — possibly more than 1,000 — of US government and private organizations since 2015.

“It’s important for us in the West to understand that we’re facing an adversary who wishes for his own reasons to do us harm,’’ said Daniel Fried, a career diplomat who oversaw sanctions imposed on Russia before retiring this year. “Whatever the domestic politics of this, Comey was spot-on right that Russia is coming after us, but not just the US, but the free world in general. And we need to take this seriously.’’

Comey’s willingness to discuss the threat in public was something of a change of heart. As FBI director, he supervised counterintelligence investigations into computer break-ins that harvested e-mails from the State Department and the White House, and that penetrated deep into the computers of the Joint Chiefs of Staff.

Yet President Barack Obama’s administration did not want to publicize those intrusions, choosing to handle them diplomatically — perhaps because at the time they looked more like classic espionage than an effort to manipulate American politics.

Comey’s special agents failed to react aggressively to evidence of the breach of the Democratic National Committee, spending nine months exchanging phone calls and vague warnings with young information-technology specialists at the committee while Russian intelligence agencies cleaned out the organization’s e-mails.

Only when e-mails from Hillary Clinton’s presidential campaign began showing up on WikiLeaks and other sites did the bureau recognize the scope of the operation.

In October, Comey declined to sign a statement publicly accusing Russia of meddling in the election — not because he doubted the evidence, aides later said, but because he did not want to interrupt the investigation.

Now many members of Obama’s national security team say they wish they had raised the alarm about Russia earlier.

There is no evidence that the Russians have stopped. The NSA suspects that a group calling itself the Shadow Brokers, which has published tools used by the agency to breach foreign computer networks, is a front for Russia, probably the GRU, the military intelligence arm.

The recent leak of a classified NSA document, for which a contractor has been arrested, provided evidence that the GRU was trying to penetrate a company that provides election software to the states, perhaps to cause havoc.

That data may be useful in future races.

Graham Allison, a longtime Russia scholar at Harvard, said, “Russia’s cyberintrusion into the recent presidential election signals the beginning of what is almost sure to be an intensified cyberwar in which both they — and we — seek to participate in picking the leaders of an adversary.’’

The difference, he added, is that American elections are generally fair and so “we are much more vulnerable to such manipulation than is Russia,’’ where results are often preordained.