Then-Sen. Barack Obama checks his BlackBerry on the 2008 campaign trail in St. Louis. (Jae C. Hong/AP)

President Obama is great at getting Twitter followers — he has 34.5 million of them — but he barely follows any of his international counterparts. All told, Obama, the White House and the State Department follow a grand total of four world leaders: Russia's @medvedevrussiae, Britain's @Number10gov, the Norwegian Prime Minister @jensstoltenberg and Chilean President @sebastianpinera. What's worse, they never talk to one another online.

That's according to the latest edition of an annual study of online diplomats from Burson-Marsteller. Although 78 percent of world leaders are on Twitter, with European leaders the most likely to be using it, their level of diplomatic engagement on the service varies. The award for best-connected world leader goes to Carl Bildt, the former prime minister of a country that gives its national Twitter handle to a different citizen every week. Bildt and 44 other global statesmen are mutual followers on Twitter.

But Bildt is something of an anomaly. Few if any national leaders tweet using their own thumbs. Only a third of the roughly 227 top ministers or heads of government that Burson-Marsteller profiled can say they represent themselves on social media. Of those, only 14 tweet on any kind of regular basis.

If digital diplomacy were really taking off, we might expect it to help maintain relationships among world governments, or at least serve as a cheap way to engage in posturing amid international negotiations. Instead, the State Department's social media efforts are floundering.

When Hillary Rodham Clinton stepped down as secretary of state in February, a lot of people wondered about the future of the geeky program she helped put together to make social media a new cornerstone of American diplomacy. Under Clinton, the State Department launched countless Twitter profiles and embassy Facebook pages, the better to engage with foreign publics.

But the effort hasn't all gone well. According to an inspector general's report, the State Department spent more than $600,000 to increase Facebook "likes," buying the kind of achievements that public diplomacy is supposed to create organically.

The new secretary of state, John F. Kerry, hasn't done anything to diminish digital diplomacy in the wake of Clinton's departure, as a lot of people feared might happen. But that's largely because Clinton set the bar so low.