It was a brief passage in the State of the Union address, but it might well prove to be one of the more consequential. In one short sentence, President Barack Obama informed Congress about his intention to launch negotiations on a Transatlantic Trade and Investment Partnership with the European Union. For decades advocates on both sides of the Atlantic have been arguing for a more comprehensive agreement. Now it finally seems within reach.

The case for closer economic ties across the Atlantic is strong. The United States and Europe remain each other's most important economic partners, and together are responsible for almost 50 percent of the world's GDP and 30 percent of global trade. Europe accounts for half of U.S. investments abroad -- some $2.1 trillion in 2011 -- and remains the most important source of foreign direct investment in the United States. More than 13 million jobs on both sides of the Atlantic are supported by transatlantic trade and investment.

Trade barriers are already low between the United States and Europe, but the size and interdependency of the transatlantic economy means that even small improvements could yield significant gains. According to a study commissioned by the European Commission, eliminating or harmonizing half of all remaining non-tariff restrictions on transatlantic trade would add 0.7 percent to the EU's and 0.3 percent to the American economy by 2018.

Opening more opportunities for trade in services between the two sides, meanwhile, could create considerable gains, as services account for more than 70 percent of EU and U.S. GDP. To be sure, a transatlantic deal would not solve all economic problems on either side of the Atlantic. But as fiscal conditions tighten and unemployment numbers remain stubbornly high, policy makers can hardly afford to pass on such an economic stimulus.

And there's more. A successful Transatlantic Trade and Investment Partnership could lead to much needed progress for global trade at a time when multilateral negotiations have come to a standstill. As a 2012 joint report by the German Marshall Fund and the European Center for International Political Economy noted, the U.S. and Europe "remain giants of the world economy and the global players still best equipped to provide global economic leadership." The sheer size of the transatlantic economy means that any agreement between the United States and Europe will be too significant to ignore elsewhere.

It's clear that the standards set in such a comprehensive deal would have global implications and could help to promote rules-based principles and international norms on everything from intellectual property rights to labor and environmental standards. In addition, a EU-U.S. trade agreement could breathe new life into the transatlantic relationship at a time when Washington is pivoting to Asia and Europe remains mired in a deep economic crisis.

For sure, none of this will be easy, and some of the trickiest hurdles remain -- from agriculture and regulatory issues to government procurement. But a transatlantic trade deal already has robust support in Europe from both German Chancellor Merkel and British Prime Minister Cameron. Now, with the U.S. president joining his European counterparts in supporting a deal, the visionary leadership necessary for taking the transatlantic relationship might finally be there.