CAMBRIDGE – Russian President Vladimir Putin’s covert aggression in Ukraine continues – and so do Western sanctions against his country. But the economy is not all that is under threat; Russia’s soft power is dwindling, with potentially devastating results.

A country can compel others to advance its interests in three main ways: through coercion, payment, or attraction. Putin has tried coercion – and been met with increasingly tough sanctions. German Chancellor Angela Merkel, Putin’s main European interlocutor, has been expressing her frustration with Russian policy toward Ukraine in increasingly harsh terms. Whatever short-term gains Putin’s actions in Ukraine provide will be more than offset in the long term, as Russia loses access to the Western technology it needs to modernize its industry and extend energy exploration into frontier Arctic regions.

With Russia’s economy faltering, Putin is finding it increasingly difficult to employ the second tool of power: payment. Not even oil and gas, Russia’s most valuable resources, can save the economy, as Putin’s recent agreement to supply gas to China for 30 years at knockdown prices demonstrates.

This leaves attraction – a more potent source of power than one might expect. China, for example, has been attempting to use soft power to cultivate a less threatening image – one that it hopes will undermine, and even discourage, the coalitions that have been emerging to counterbalance its rising economic and military might.

A country’s soft power rests on three main resources: an appealing culture, political values that it reliably upholds, and foreign policy that is imbued with moral authority. The challenge lies in combining these resources with hard-power assets like economic and military power so that they reinforce one another.

The United States failed to strike this balance with respect to its 2003 invasion of Iraq. While America’s military power was sufficient to defeat Saddam Hussein’s forces quickly, it did so at the expense of its attractiveness in many countries. Likewise, though establishing a Confucius Institute in Manila to teach Filipino people about Chinese culture may help to cultivate China’s soft power, its impact will be severely constrained if China is simultaneously using its hard power to bully the Philippines in the territorial dispute over the Scarborough Shoal.

The problem for Russia is that it already has very little soft power with which to work. Indeed, as the political analyst Sergei Karaganov noted in 2009, Russia’s lack of soft power is precisely what is driving it to behave aggressively – such as in its war with Georgia the previous year.

To be sure, Russia has historically enjoyed considerable soft power, with its culture having made major contributions to art, music, and literature. Moreover, in the immediate aftermath of World War II, the Soviet Union was attractive to many Western Europeans, owing largely to its leadership in the fight against fascism.

But the Soviets squandered these soft-power gains by invading Hungary in 1956 and Czechoslovakia in 1968. By 1989, they had little soft power left. The Berlin Wall did not collapse under a barrage of NATO artillery, but under the impact of hammers and bulldozers wielded by people who had changed their minds about Soviet ideology.

Putin is now making the same mistake as his Soviet forebears. Despite his 2013 declaration that Russia should be focusing on the "literate use” of soft power, he failed to capitalize on the soft-power boost afforded to Russia by hosting the 2014 Winter Olympic Games in Sochi.

Instead, even as the Games were proceeding, Putin launched a semi-covert military intervention in Ukraine, which, together with his talk of Russian nationalism, has induced severe anxiety, particularly among ex-Soviet countries. This has undermined Putin’s own stated objective of establishing a Russia-led Eurasian Union to compete with the European Union.

With few foreigners watching Russian films, and only one Russian university ranked in the global top 100, Russia has few options for regaining its appeal. So Putin has turned to propaganda.

Last year, Putin reorganized the RIA Novosti news agency, firing 40% of its staff, including its relatively independent management. The agency’s new leader, Dmitry Kiselyov, announced in November the creation of "Sputnik,” a government-funded network of news hubs in 34 countries, with 1,000 staff members producing radio, social media, and news-wire content in local languages.

But one of the paradoxes of soft power is that propaganda is often counterproductive, owing to its lack of credibility. During the Cold War, open cultural exchanges – such as the Salzburg Seminar, which enabled young people to engage with one another – demonstrated that contact among populations is far more meaningful.

Joseph S. Nye, Jr. is a professor at Harvard University, Chairman of the World Economic Forum’s Global Agenda Council on the Future of Government, and the author of The Future of Power.