Sputnik, a radio station funded by the Russian government, is broadcasting from the heart of the nation's capital. (Jonathan Newton/The Washington Post)

PRESIDENT VLADI­MIR PUTIN is a fresh convert to the principle of reciprocity in his dealings with the United States. He ought to take it a step further.

On Friday, the Russian leader, irked at a sanctions bill that sailed through Congress, confiscated two American diplomatic properties in Russia and ordered the expulsion of diplomats and other staff from the U.S. Embassy in Moscow. The moves matched sanctions that President Barack Obama slapped on the Kremlin in response to Russian meddling in the 2016 presidential election.

As long he’s into reciprocity, Mr. Putin might take notice that while Moscow continues to banish U.S. international news outlets from Russian airwaves, Kremlin-funded mouthpieces such as Sputnik radio have enjoyed a field day in the United States, taking advantage of America’s open society to sow misinformation and distrust.

As reported by The Post’s Justin Wm. Moyer, Sputnik, Moscow’s main radio propaganda outlet, has taken over a bandwidth on the District’s radio dial, 105.5 FM, formerly occupied by a bluegrass station, and began airing broadcasts July 1 from offices in downtown Washington, three blocks from the White House.

Meanwhile, there has been no change in Russia’s decade-long banishment of U.S. government-funded outlets airing programs on Russian television airwaves, or Russian-language broadcasts from Voice of America and Radio Free Europe/Radio Liberty, which were banned by a 2012 law.

Mr. Trump should also take notice. Speaking to reporters aboard Air Force One recently, he said, “To me, the word reciprocal is a beautiful word.” As it happens, he was talking about international trade, an area in which he thinks Americans get a bad deal.

Yet in the realm of U.S.-Russian international news, reciprocity seems absent from Mr. Trump’s radar. A 24/7 Russian-language television venture produced by Voice of America and Radio Free Europe/Radio Liberty, called Current Time, has been up and running for several months, producing high-quality news, but is available only online.

The asymmetry is a problem. Mr. Putin’s government, intent on undermining liberal democracies by casting doubt on the very notion of truth, and sowing division and doubt about basic Western institutions, has become increasingly adept at weaponizing information. U.S. intelligence agencies have called attention to Moscow’s fake news campaign, as have U.S. allies in Europe.

English-language shows on Sputnik and, secondarily, RT — the Kremlin’s not-much-watched but widely available English language television mouthpiece — feature useful American dupes and others who need no instruction from Moscow to reinforce the narrative, already current on the extreme left and right of Western politics, that U.S. capitalism, elections, institutions and media are corrupt. They trade in moral equivalence, eliding the plain fact that the Russian government — cynical, brutal and heedless of democratic norms — pursues interests and subscribes to values antithetical to those prized by most Americans.

The wild disparity in access accorded by Moscow and Washington to each other’s government-sponsored media outlets is unsustainable. If Mr. Trump is a champion of reciprocity, as he asserts, then U.S. diplomats should demand reciprocal treatment for Voice of America and Radio Free Europe/Radio Liberty. And if Mr. Putin has embraced reciprocity, he should be prepared to live by it.