As a new Russia-related scandal sweeps Washington, it's impossible not to recall Russian President Vladimir Putin's efforts in 2012 to make meetings with the U.S. ambassador to Moscow toxic. As Trump's opponents seek to inflict maximum damage for Attorney General Jeff Sessions' false denial about a meeting with a Russian envoy, they should understand where these games lead.

For Putin, whose suspicion of foreign diplomats was nurtured during his years as an intelligence officer, it began in 2007. "Unfortunately, there are still those in our country who scavenge at foreign embassies, counting on the support of foreign foundations and governments rather than the support of their own people," Putin famously told a rally of his supporters in 2007. The word Putin used for "scavenge" — "shakalit" — is derived from the Russian word for "jackal."

Still, Putin didn't really make it difficult for Russians to seek out foreigners for financial support or attend embassy receptions to network until the beginning of his third presidential term in 2012.