Jim Hoagland is a contributing editor to The Post. His e-mail address is jimhoagland@washpost.com.

Round Two of the strategic tug-of-war between the European Union and Russia over Ukraine has gone to the Kremlin. But the political struggle at Europe’s eastern gates is not over. Europe must renew its support for Ukraine’s democratic forces not only for their sake but also to revitalize the European Union’s own flagging sense of purpose.

The 28-nation union has been on a high-speed roller coaster, plunging from a peak of self-congratulatory smugness over its successful political integration into a trough of economic turmoil and disunity. Political leaders and economists at a high-level conference here last weekend agreed that Europe is emerging from the worst of the financial turmoil, with the euro surprisingly strong. But, they acknowledged, the recovery is moving at an agonizingly slow, uneven pace.

This uncertainty accounts in part for the caution that European capitals have shown toward the popular uprising against Ukrainian President Viktor Yanu­kovych and his decision to defer closer links to the E.U. in favor of accepting greater cooperation with (and a $15 billion subsidy from) Russia. The Obama White House, still intent on pursuing arms control and other deals with Russia, has also been careful not to cross the Kremlin on Ukraine.

No such inhibitions trouble Russian President Vladimir Putin, who sees Ukraine as the last existential battle of the Cold War. As he did in 2004, when the Orange Revolution seemed on the verge of bringing a Western-style democracy to power in Kiev, Putin has fought in Ukraine to secure the survival of his own counterrevolutionary regime in Moscow. Four decades after the domino theory was discredited for Americans in the rice paddies of Southeast Asia, it is alive and well at the Kremlin.

To be sure, the West is poorly positioned to compete with Russia for direct economic or political advantage in Ukraine. Ukrainians themselves are split over the sacrifices involved in giving up Russian markets and financial aid to gamble on moving into the European Union’s modern economic superstate.

But the protesters who have braved freezing weather and police intimidation in Kiev and elsewhere understand that theirs is, above all, a struggle about moral authority. For all of their problems, the rules-based E.U. societies are a magnet for Ukrainians disgusted with the corruption and lawlessness of their leaders and Russia’s. Formal association with Europe would help establish the rule of law and limit the government’s power to abuse and neglect its own citizens.

No wonder Putin does not want to see a functioning, European-style democracy on his western frontier. Conversely, European and American leaders must entrench this moral authority in their support of Ukrainian people power and do nothing to diminish it by seeming to condone or ignore Putin’s meddling.

When Laurent Fabius, France’s highly competent foreign minister, spoke at the World Policy Conference here last weekend, he was challenged from the audience after he failed to mention Ukraine on a list of urgent international issues that demanded the group’s attention. Those attending included political, business and religious leaders as well as intellectuals and opinion-makers. The spirited discussion that followed reflected broad support for the cause of the Ukrainian protesters as a moral obligation to help a neighbor in trouble.

But more immediate and dispiriting concerns dominated the rest of the three-day gathering, with Europeans accepting that they are unlikely to be able to continue to finance their generous social welfare states at current levels, voicing concern that anti-European populist parties will score impressive gains in spring elections for the European Parliament and agonizing over the strains that they see immigration from Africa and the Middle East inflicting on their countries.

Six years of anemic or no growth, rising unemployment in Europe’s southern region and political upheaval just across the Mediterranean have taken a heavy toll on the European Union’s once-confident élan. Established to prevent wars between Europe’s most powerful nations and to promote continent-wide prosperity, the union finds itself bogged down in esoteric arguments over banking supervision and confronting rising currents of nationalist sentiment.

Helping Ukraine escape the clutches of its own and neighboring despots is a big challenge, one worthy of the creative spirit that European leaders demonstrated in founding their union half a century ago. They were given essential support in that task by wise American leaders who did not see U.S. leadership in global affairs as a glass half-empty, as it seems this White House often does.