President Obama has returned from his grand tour of Europe that took in Ireland, Britain, France and Poland. While overseas, he was feted by large crowds and fawned over by European political elites.

Even in London, he was given a hugely warm welcome. Despite an embarrassing track record of insulting America’s closest friend and ally, he was rewarded with a state visit and the honor of an address to Parliament.

Despite all the fanfare, Barack Obama still doesn’t come across as an American leader of weight, principle or conviction. His flagship speech in Westminster Hall was full of soaring rhetoric and forced platitudes about the importance of the Anglo-American alliance, but was ultimately empty when it came to policy. There was no clear vision for U.S. leadership in the Middle East, including the war in Libya, the crisis in Syria and the growing Iranian nuclear threat. On Afghanistan, where more than 100,000 U.S. troops are fighting the Taliban, there was only talk of an endgame, and no sense of striving for victory.

And there was even less detail on offer in the president’s joint press conference at Downing Street with David Cameron, where the British Prime Minister spectacularly outshone and outclassed his dull and uninspiring U.S. counterpart. Without the presence of his beloved teleprompter, Mr. Obama was left floundering in the face of straightforward questions from the American and British press. When asked about the budget deficit, the president delivered an embarrassingly muddled response that hardly exuded confidence. On Libya he was even worse, forcing Mr. Cameron to explain America’s role in the campaign to oust Col. Moammar Gadhafi. What the White House appropriately calls “leading from behind” was amply on display in London last week for all to see.

In many ways, Mr. Obama’s leadership is the antithesis of Ronald Reagan‘s, which might explain why Lech Walesa, the hero of the Polish Solidarity movement, declined to meet the U.S. president when he went to Warsaw on Saturday. In marked contrast to Reagan, Mr. Obama does not believe in American exceptionalism or the powerful projection of American global power. Nor does he believe in the kind of investment in America’s military that is required to maintain the nation’s unique status as the world’s only superpower.

Reagan also invested a great deal of effort in building and strengthening alliances, as well as aggressively advancing the cause of freedom on the world stage. For Mr. Obama, spending time with leaders from Eastern and Central Europe, nations that were liberated just two decades ago from Soviet tyranny thanks to the policies of Reagan and Margaret Thatcher, is a chore rather than a blessing. For the Obama doctrine has been largely about engaging America’s enemies rather than cultivating traditional allies, and “resetting” relations with Russia has been a far more important goal than working with the Poles, Czechs and Baltic States for example.

Unquestionably, Mr. Obama has been the weakest U.S. leader since Jimmy Carter. He has largely placed U.S. foreign policy on autopilot, reacting to international crises with slothlike speed and without a clear strategy in place. It is indeed a sad day for America when even the French president is more energized on world affairs than the leader of the free world.

Mr. Obama’s European tour has been hailed by his supporters in the liberal media as a major success. In reality, it only further underscores how little depth there is to Mr. Obama’s world leadership at a time of mounting global threats and economic turmoil. The international community may be looking to the White House for powerful leadership on an array of pressing issues, but will invariably find the U.S. president AWOL or unwilling to lead.

Nile Gardiner is the director of the Margaret Thatcher Center for Freedom at the Heritage Foundation