The Republican-controlled Congress does not trust President Trump on Russia or on sanctions. As a result, the House is now considering legislation passed by the Senate that would severely limit the administration’s flexibility regarding sanctions on Russia. How deep is the problem? The Senate approved the legislation on June 19 by a vote of 98-2, ignoring Secretary of State Tillerson’s plea just two days earlier.

Executive Sanctions

The Obama administration issued four executive orders applying sanctions on Russia after Moscow’s illegal seizure and annexation of Crimea in March 2014. Initial sanctions targeted individuals. More serious sanctions targeting certain sectors of the Russian economy followed when the Kremlin inspired and supported armed separatism in eastern Ukraine—particularly after the July 2014 shoot-down of a Malaysia Air Boeing 777 by a Russian-provided missile. While estimates are imprecise, some believe that U.S. and European Union sanctions have cut Russia’s gross domestic product by one percent.

In December 2016, the Obama administration issued another executive order, which applied sanctions on Russian intelligence agencies—the Main Intelligence Directorate (military intelligence) and the Federal Security Service—as well as individual Russians. That order was a response to Moscow’s interference in the U.S. presidential election.

Sanctions based on executive orders leave the decision to raise or lower them entirely with the executive branch. As a general rule, presidents—both Democrats and Republicans—have prized that flexibility and sought to protect it.

Congress Gets into the Act

Capitol Hill began seriously considering legislation to codify the Ukraine- and election-related sanctions in law earlier this year. That resulted from a lack of confidence in how Mr. Trump would handle sanctions and Russia.

Candidate Trump had suggested that he might ease sanctions on Moscow without necessarily getting anything in return, such as implementation of the February 2015 Minsk agreement to settle the conflict in eastern Ukraine. While his spokesperson has since said those sanctions will remain in place, that has not mollified Congress. Moreover, the president seems blithely unconcerned about Russia’s interference in the U.S. election and has done nothing to try to deter Moscow from future election-hacking.

The Senate thus passed legislation that codifies the Obama executive orders in law and requires Congressional approval or a presidential waiver before sanctions can be lifted. It also authorizes additional sanctions on Russia. The House is now considering the Senate bill. While the White House reportedly is lobbying to soften its terms, Speaker Ryan on June 22 expressed support for sanctions and said he wants “to get moving on [the bill].”

The Impact of Congressional Sanctions

Congressionally-mandated sanctions will tie the president’s hands and will likely have the unintended effect of devaluing the sanctions as a tool to encourage a change in Russian behavior. The reason: Congress has a track record of applying sanctions quite easily but taking far more time to remove them.

For Moscow, the 1974 Jackson-Vanik Amendment offers the prime example of this. Jackson-Vanik denied permanent normal trade relations status with the United States to the Soviet Union until religious minorities—primarily Soviet Jews—were allowed to emigrate. The amendment applied to the post-Soviet states after the Soviet Union’s collapse in 1991.

Russia almost immediately permitted open emigration. Hundreds of thousands of Russian Jews left in the early 1990s for Israel, Europe, and the United States. The Clinton administration found Russia in full compliance with Jackson-Vanik’s provisions in 1997, yet it took Congress another 15 years to graduate Russia from the amendment. And Congress only removed Russia from the Jackson-Vanik provisions in the 2012 Magnitsky Act, which applied new sanctions on Russia.

If Moscow believes that Congressional sanctions will remain in place for years and years after it makes the desired policy change, it will have less incentive to make the change.

A Challenge for Trump

The House will probably pass the sanctions legislation. Mr. Trump can then sign or veto. Congress has muddied the waters by putting the Russia sanctions language in a bill regarding additional sanctions on Iran. The administration supports the latter.

The White House has to find a way to persuade Congress that Mr. Trump has got religion on sanctions.

A presidential veto would provoke a major outcry on Capitol Hill, including from many Republicans. And it likely would prove futile. By all appearances, Congress would have the votes to override the veto, putting the sanctions into law and handing the president an embarrassing political defeat.

Can the president do anything to avert this? The White House has to find a way to persuade Congress that Mr. Trump has got religion on sanctions and understands that the United States should impose consequences on Russia for its election meddling. That will not be easy; aside from a few of his signature tweets asserting that the Obama administration did nothing to respond to the Russian hacking, Mr. Trump barely even acknowledges that there is a problem.

In this regard, lots of eyes will be watching the expected meeting with Russian President Putin on the margins of the G-20 meeting in Hamburg on July 7 and 8. Mr. Trump needs to raise the hacking issue and starkly warn Mr. Putin against a repetition. If he fails to do that, he should expect to return home to a firestorm of criticism … and guaranteed Congressional passage—with a veto-proof majority—of the Russia sanctions legislation.