Collusion — or a lack of it — turns out to have been the rhetorical trap that ensnared President Trump’s pursuers. There was no need for detailed electoral collusion between the Trump campaign and Vladimir Putin’s oligarchy because they had an overarching deal: the quid of help in the campaign against Hillary Clinton for the quo of a new pro-Russian foreign policy, starting with relief from the Obama administration’s burdensome economic sanctions. The Trumpites knew about the quid and held out the prospect of the quo.

Run down the known facts about the communications between Russians and the Trump campaign and their deal reveals itself. Perhaps, somewhere along the line, Russians also reminded the Trump family of their helpful cooperation with his past financial ventures. Perhaps, also, they articulated their resentment of Mrs. Clinton for her challenge as secretary of state to the legitimacy of Mr. Putin’s own election . But no such speculation is needed to perceive the obvious bargain reached during the campaign of 2016.

Early on, emissaries of the Russian oligarchs sent word of their readiness to help embarrass and undermine the Clinton candidacy. And in June 2016, the Russians lured the Trumpites to a meeting in Trump Tower with a promise of “dirt” against Mrs. Clinton only to use the meeting to harp on their hunger for sanctions relief. As the Trump family openly acknowledged, the Russians spoke at that meeting of a desire to again allow Americans to adopt Russian children. Since the adoptions were halted to retaliate against the American sanctions, it required no dictionary to interpret the oligarchs’ meaning: “dirt” for sanctions relief.

That relief and a warm new relationship with Russia were then freely discussed in public and in private. There was even an effort to concoct a grand diplomatic bargain by which the Russians would be allowed to legalize their seizure of the Ukrainian Crimea. Michael Cohen and other Trump advisers promoted the idea of letting the Russians “lease” the seized territory for up to 100 years so as to sanitize the reciprocal lifting of the sanctions that Mr. Obama had imposed to punish the land grab.