Deterrence can also take the form of limiting the Russians’ ability to buy media muscle covertly. Global finance is still gangsters and the spooks’ best friend, allowing them to secretly move and spend money. By joining the Organization for Economic Cooperation and Development’s latest and most stringent Common Reporting Standards agreement for sharing financial information, for example, and by putting pressure on American states with notoriously tough secrecy laws, Washington would make it harder for not just corrupt Russians officials but also Moscow’s security apparatus to spend money at will in America.

But the United States also needs to declare in advance, and with evident resolve, the kinds of actions it would take in response to certain political attacks. Russia has been taking advantage of the weaknesses and freedoms of the West, so the West should similarly strike back against Russia’s vulnerabilities.

For example, punitive measures like sanctions can be a very powerful weapon against the opportunist kleptocrats on whom Mr. Putin relies for support. Media owners whose networks spread disinformation, members of Parliament who cultivate extremists, and oligarchs who allow themselves to be used as Kremlin front men should all be fair game. Treating them like members of an organized crime syndicate would allow Washington to freeze not only their assets, but also those of their families, and bar them from entry.

The West also needs to stand together against the Kremlin’s divide-and-rule tactics. NATO members are committed by treaty to defending one another from military attacks, but there aren’t similar provisions for cyberattacks or information warfare. Many smaller countries hesitate to play their part in fighting Russian espionage and subversion — whether expelling spies or closing front organizations — because they fear Russia’s inevitable retaliation. The United States needs to promise its allies it will support them.

Finally, Mr. Putin’s own vanity could be turned into a weapon against him. Every time he overreaches, the American government should point it out. Every time he fails, we need to say so loudly and clearly. We should tell jokes about him. He can rewrite the record in Russia, but the West does not have to contribute to his mythmaking — and we should stop building him up by portraying him as a virtual supervillain.

All of this requires a new mind-set. It means accepting that Russia has chosen to be at war with us — albeit a special and limited war. Russia needs to be treated as a political combatant.

It also means remembering how much stronger the United States is than Russia, economically, militarily, diplomatically and even politically. Mr. Putin is a geopolitical guerrilla who has adopted a strategy he hopes can play to his own strengths and circumvent the West’s. Now the West needs to demonstrate that it has a strategy to combat his adventurism.