Part of the Russian operation’s success is that we cannot measure the effect. Did the DNC emails depress the Sanders vote for Clinton? Did the Podesta emails turn off independents? Would voters have responded differently if major media had reported the email releases not as legitimate news but as an intelligence operation by a hostile foreign power aimed at undermining the integrity of U.S. elections? There are no clear answers. But there are certainties: The email operation increased negative stories about Clinton, fueled an immense propaganda attack and diminished coverage of actual issues. The large polling lead Clinton gained after the debates slipped significantly under this barrage of negativity — even before FBI Director James B. Comey’s bombshell.

Again, was there coordination with this foreign intervention? Russia’s deputy foreign minister, Sergei A. Ryabkov, boasted that government representatives maintained multiple “contacts” during the campaign with Trump’s “immediate entourage.” (Campaign spokeswoman Hope Hicks issued a denial.) This is on top of reported U.S. government suspicions that a Trump adviser met with the intelligence operative directing the hacking. Where are the committee chairmen in Congress demanding an investigation? How is it that Republican Party leaders accept the intervention of a foreign power in the election of their party’s presidential candidate?

Putin is pursuing large strategic goals: recognition of the annexation of Crimea and international acceptance of foreign aggression to change state borders; Russian control of Ukraine; weakening or even dissolution of the European Union and NATO; restoration of Russia as a great power; and restored dominance over the former Soviet bloc and its environs. In pursuing these aims, Putin is engaged in a disciplined effort to influence democratic politics in the West, including financial and propaganda support for the narrow Brexit victory and for a network of far-right (and pro-Russian) nationalist political parties and groups throughout Europe. Now he has achieved what had to have been his most improbable goal: helping elect a sympathetic U.S. president who wants to form an alliance against terrorism. What will Trump give in exchange? He has already reaffirmed his intention to end support for pro-Western rebels in Syria, which effectively gives Russia a free hand to make President Bashar al-Assad its satrap. The greater danger is Trump’s attitude toward NATO as a “soft” alliance that, like the Western powers in 1939, won’t “die for Danzig.” It would mean the alliance’s end.