President Trump meets with Russian President Vladimir Putin. (Evan Vucci/Associated Press)

AFTER WE learned that Donald Trump Jr. said he would “love” to receive campaign help from the Russian government, it was pointed out that Russia is a hostile power. This is true, but what does it mean? It’s worth revisiting the question, because the answer has a lot to do with what Russian President Vladi­mir Putin stood to gain by interfering in the United States’ 2016 presidential election.

“Hostile,” in this case, doesn’t mean that Russia and the United States are about to go to war. In theory, their interests shouldn’t even diverge all that much. They are two continental powers on opposite sides of the world with no territorial disputes (though the melting of Arctic ice may change that). They share a fear of Islamist terrorism.

What makes Russia hostile is Mr. Putin’s adherence to, and dependence on, a set of values that are antithetical to what have been, at least until now, bedrock American values. He favors spheres of influence over self-determination; corruption over transparency; and repression over democracy. His antipathy toward Hillary Clinton was not personality-driven but based on her advocacy of values that would threaten his rule.

It’s sometimes hard for Americans to understand the gulf between the two nations because Mr. Putin has maintained the trappings of democracy — a parliament, national elections — even as he has made them meaningless by shuttering most independent media and eliminating most political opposition. The state now serves Mr. Putin and his cronies, who have become immensely wealthy, rather than the reverse. When people try to expose the corruption, they are imprisoned or killed (or both, as in the case of lawyer Sergei Magnitsky). When Mr. Putin stakes out any position, the first question on his mind is not “Is this good for Russia?” but rather: “Will this help my regime to survive?”

(Adriana Usero,Kate Woodsome/The Washington Post)

Ukraine, which like Russia was part of the Soviet Union, provides a useful example. This is a country the size of France that lies between Russia and the rest of Europe. When it started to move in a more democratic direction, Mr. Putin felt threatened on two counts. First, a democratic Ukraine would not be as open to plunder as one ruled by oligarchs; second, if a democratic Ukraine prospered, it might give ordinary Russians dangerous ideas. Ms. Clinton, as secretary of state and after, supported Ukraine’s democratic aspirations. Mr. Putin invaded the country, seized part of its territory and initiated an ugly civil war that helps keep Ukraine from prospering.

It may be true that Mr. Putin’s hacking and fake-news campaign began as an effort simply to damage Ms. Clinton’s reputation on her road to the White House or to make the democratic process look as ugly as possible. But along the way, Mr. Putin must have realized that Donald Trump’s policies aligned with his values more than he could have dared expect from any American candidate. Mr. Trump disparaged democratic allies and alliances while expressing admiration for dictators. He appeared willing to mingle private business with public duties in unprecedented ways, while elevating family members in the style of a Central Asian caesar. At home, he echoed Mr. Putin in his cynical disparagement of a free press, his celebration of violence at his rallies, and his ugliness toward Muslims, Mexicans and others he perceived or portrayed as outsiders.

So while the younger Mr. Trump may have seen advantage in accepting Russia’s help, Russia certainly would have seen an advantage in proffering it. Mr. Putin’s values are antithetical to American values, but the Russian dictator had good reason to hope that they would not be antithetical to the values of a Trump administration.