SKOPJE, Macedonia — As Macedonians prepare for the most important vote in their nation’s history, scores of Facebook posts are urging voters to burn their ballots. Hundreds of new websites are calling for a boycott. And one news article, widely shared online, warns that Google may eliminate Macedonian from its list of recognized languages, depending on the vote.

In a disinformation age, Macedonian and Western officials say the flurry of social media activity is just that — disinformation directed by Russian-backed groups trying to stoke fears and depress turnout in a vote that could put this Balkan nation on a path to join NATO.

And the West is trying to fight back, albeit unevenly: A congressional effort to confront Russian disinformation has been hamstrung by divisions in Washington. To fill the void, Defense Secretary Jim Mattis traveled to Skopje, the country’s capital, on Monday to show American support. Jens Stoltenberg, the NATO secretary general, has already visited, as have Chancellor Angela Merkel of Germany and Federica Mogherini, the European Union’s foreign policy chief.

All have a simple message: It’s now or never.

“There is no going back from this,” said Prime Minister Zoran Zaev of Macedonia. “Each attempt to hinder these processes takes the Republic of Macedonia back to a state of complete uncertainty about its future, a society in which the authoritarian values and instability could be reintroduced.”