LONDON – When Russian soldiers entered Ukraine and captured Crimea in 2014, the Obama administration responded with a list of economic sanctions that ultimately imposed sanctions on hundreds of Russian officials and companies and restricts investment and trade in the country’s crucial financial, oil and military sectors.

Now, with Russian troops massing on the Ukrainian border, the White House national security adviser said President Biden had looked Russian President Vladimir V. Putin in the eye this week “and said things to him. that we didn’t do in 2014, we’re ready to do now.

However, it is far from clear whether tougher measures would persuade Russia to stay out of Ukraine. Historically, economic sanctions have a resolutely mixed results, with no more failures only successes. And the actions that would have the biggest impact on the Russian economy – like trying to severely restrict oil exports – would also be difficult for U.S. allies in Europe.

“We have seen it time and time again, that sanctions have a hard time forcing really big policy changes,” said Jeffrey Schott, senior researcher at the Peterson Institute for International Economics who has spent decades researching on the subject. “It’s a limited toolbox. “

The best chance of success is when one country has significant economic clout over the other and the political focus is limited, Mr Schott said – but neither of those conditions really apply in this case. Mr. Putin has made it clear that he sees Russia’s actions in Ukraine as a matter of national security. And outside of the oil industry, Russia’s international trade and investment is limited, especially in the United States.

With direct military intervention essentially off the table, officials in the Biden administration have listed a series of options that include financial punishment of Mr. Putin’s closest friends and supporters, blocking the conversion of rubles to dollars and pressure on Germany to block a new gas pipeline between Russia and Northern Europe as soon as it opens.

Work on this pipeline – called Nord Stream 2 – has been completed, but it is awaiting approval from the German energy regulator before it can begin operation.

Any request from Washington would coincide with a change of leadership in Berlin. The new Chancellor, Olaf Scholz, and his cabinet were sworn in on Wednesday. He has yet to make any final statements on the pipeline. However, gas reserves are unusually low in Europe today, and concerns remain about shortages and soaring prices as winter approaches.

Russia supplies more than a third of Europe’s gas through the existing Nord Stream gas pipeline and has previously been accused of suspending supply in order to pressure Germany to approve Nord Stream 2.

Washington could impose much more drastic sanctions on certain companies and banks in Russia, which would more severely reduce investment and production in the energy sector. The risk of severe sanctions against a company like Gazprom, which supplies natural gas, is that Russia could retaliate by cutting its deliveries to Europe.

“It would hurt Russia a lot, but also Europe,” Schott said.

In terms of increasing the pressure, James Nixey, director of the Russia-Eurasia program at Chatham House think tank, suggested that financially crushing the oligarchs who help Mr Putin maintain power could be a way to exercise more targeted pressure.

“I would attach great importance to continuing the inner and outer circles around Putin, which have ties to the regime,” he said.

For now, the whirlwind of ambiguity over possible US actions is helpful, he added: “It’s pretty good if the Russians keep guessing.”

Russia, the United States and the European Union – which on Wednesday offered to expand their power to use economic sanctions – all play a guessing game in order to further their political goals. Russia is deploying troops to the border and at the same time insisting on guarantees that Ukraine will not join NATO, while the West warns that an invasion will have painful economic consequences.

One of the most extreme measures would be to cut Russia off from the international payments system known as SWIFT which moves money around the world, as has been done to Iran.

In 2019, then Russian Prime Minister Dmitry A. Medvedev called such a threat equivalent to “a declaration of war”.

Maria shagina argued in a report for the Carnegie Moscow Center that such a move would be devastating for Russia, at least in the short term. “The cut would end all international transactions, trigger currency volatility and cause massive capital outflows,” she said. written this year.

The SWIFT system, based in Belgium, manages international payments between thousands of banks in more than 200 countries.

Since 2014, Moscow has taken steps to mitigate the threat by developing its own system to process domestic credit card transactions, she noted. But this is another measure that would affect European countries more than the United States because they do so much more business with Russia.

Several economic and political analysts have said that restricting access to SWIFT would be a last resort.

Arie W. Kruglanski, professor of psychology at the University of Maryland, said that in assessing the impact of sanctions, economists too often overlook the crucial psychological aspect.

“Sanctions can work when leaders are more concerned about economic issues than anything else,” he said, but he doesn’t think the Russian leader falls into that category. For Mr. Kruglanski, authoritarian strongmen like Mr. Putin are motivated by a sense of their own importance, and threats are more likely to strengthen opposition than to encourage compromise.

As for Ukraine-related sanctions so far, the impact has been negligible, said Mr Nixey of Chatham House.

“A lot of these things the Russians have learned to live with, in part because the implementation has been slow or poor and the effects on the Russian economy are manageable,” he added.

Success can be defined in various ways. Mr Nixey said the 2014 measures most likely deterred the Kremlin from continuing its military interventions in Ukraine. A report for the Atlantic Council, a think tank that focuses on international relations, released this spring, came to the same conclusion.

The sanctions certainly did not force Russia to roll back its annexation of Crimea, Nixey said, but they may have persuaded Putin to take more aggressive action – at least so far.