Europe is caught in the middle of an energy crisis, and Russian President Vladimir Putin is turning the screws.

Not only has Putin been refusing to respond swiftly to requests for more gas, he has upped his harassment of Ukraine with an 80,000-troop buildup near the border, and cooperated with his client in Belarus to fuel a migrant crisis in Poland and the Baltic states.

The Biden administration this week made a public show of solidarity with Ukraine, when Secretary of State Antony Blinken hosted Ukrainian Foreign Minister Dmytro Kuleba in Washington. But it refuses to do the one thing the Ukrainian government and Congress believe could deny Putin yet another weapon to use against America’s European partners: stop the completion of the Nord Stream 2 pipeline.

“What is unfolding in Europe now is a very complicated thing with many elements to it,” Kuleba said during his visit to the State Department, adding that Putin uses cyberattacks and disinformation campaigns to destabilize Europe. “In this complicated game, we have to remain vigilant, we have to be resilient.”

Russia’s recent aggressions have become so problematic, President Biden dispatched CIA director and former ambassador William J. Burns to Moscow last week to deliver the U.S. government’s concerns to Putin personally. Part of the message was a warning to Russia against using energy exports as a political weapon against Europe. Of course, Putin has been doing that already.

Just last week, the Russian leader remarked that if Nord Stream 2 — the almost-complete gas pipeline between Russia and Germany that runs beneath the Baltic Sea — were operational tomorrow, he could increase the flow of gas to Europe “the day after tomorrow.” The truth is, Putin could turn up the spigot today if he chose. Putin doesn’t need his new pipeline to sell gas; he just wants it as another tool to control his neighbors, several of whom are NATO allies.

In that environment, why would the Biden administration allow the Nord Stream 2 pipeline to become operational? After all, during his January confirmation hearing, Blinken testified that the Biden administration was “determined to do whatever we can to prevent that completion.” Since then, the Biden team has fallen well short of that promise.

In February, the Biden administration sanctioned one pipelaying ship and its owner, even though both had been sanctioned already. Then, in May, the United States waived sanctions on the firm in charge of the project, Nord Stream 2 AG, and its chief executive. National security adviser Jake Sullivan defended the waivers on the grounds that it was a “Swiss company,” a claim fact checkers called misleading considering it is wholly owned by Gazprom, Russia’s state-owned energy conglomerate.

My Post colleagues reported Blinken was overruled by the White House regarding the sanctions. In June, Blinken called the pipeline’s completion a “fait accompli.” In July, the United States and Germany issued a “joint statement” in which Germany promised to try to convince Russia not to use the excess capacity created by Nord Stream 2 to cut its exports through Ukraine — a move that could cripple Ukraine’s economy.

The pipeline may be a “fait accompli” for the White House, but U.S. lawmakers aren’t giving up. In late September, the House passed a bipartisan amendment to the National Defense Authorization Act by Reps. Marcy Kaptur (D-Ohio) and Michael McCaul (R-Tex.) that would require the Biden administration to sanction all companies associated with the Nord Stream 2 pipeline. The White House would not have the power to issue a waiver.

Sen. Jeanne Shaheen (D-N.H.) introduced an amendment to the NDAA, co-sponsored by Sen. Rob Portman (R-Ohio), that would require the administration to report back periodically on the implementation of the U.S.-Germany “joint statement,” an effort to compel more transparency.

“I’ve long opposed the Nord Stream 2 pipeline and continue to oppose it today,” Shaheen told me. “My bipartisan amendment to the annual defense bill requires transparency from the administration on its joint statement with Germany.”

But Senate Democrats, while opposed to the pipeline in principle, are less willing to tie the administration’s hands. They haven’t yet said whether they will support adding nonwaivable sanctions to the bill.

The argument against sanctions seems rational on the surface. Who are we in the United States to tell Germany it can’t have a pipeline it wants? That stance, however, ignores the implications Nord Stream 2 has for several other allies. The Biden administration’s hope that Putin won’t weaponize it against several countries, including Germany, is either disingenuous or naive. When Putin gets powerful leverage, the pattern shows he will surely use it.

The long-term U.S. strategy should be to bolster European energy security by increasing U.S. natural gas exports there, while working with Europe to transition to a post-fossil fuel economy. But meanwhile, allowing Putin to amass even more control over Europe’s fate is counterproductive and dangerous. The good news is there’s still time to stop it.