After listening to U.S. presidential wannabes debate – and I use that word loosely, because I have yet to hear a real one in this campaign – and otherwise discuss key issues, I have a pressing piece of advice:

It’s foreign policy, stupid. And we hear too little about it.

At some point, I sincerely hope that Americans will come to grips with an imposing reality: the interconnectedness of the United States and the rest of the planet. There is no time for head-in-the-sand obliviousness or the carefree attitude that the world is America’s back yard and other countries are simply playing in it.

Although many people prattle on about so-called domestic matters – such as the ailing U.S. economy, which loomed large in President George W. Bush’s State of the Union address this week – the fact is that the once-meaningful distinction between the purely domestic and the purely foreign no longer exists. Furthermore, if we fail to tend to global problems such as terrorism, climate change and pandemics, it will not matter much what happens at home.

To lead the United States more ably into the remainder of the 21st century, Americans need a president who understands the international realm – not superficially, because he or she has been briefed, but substantively. On-the-job training should not be an option.

It is also necessary to change the U.S. image of a nose-in-the-air superpower that pursues unilateral policies and alienates much of the world. America requires a leader who can chart a common course with allies, build coalitions to deal proactively with problems and smooth over global tensions.

A good part of that effort can and should happen through economic initiatives, notably the promotion of free trade.

At this year’s World Economic Forum in Davos, Switzerland, some participants, citing U.S. economic weakness, hinted of a “new economic order.” A few even went so far as to suggest that certain nations could effectively decouple from the effects of an economic downturn in America by reducing reliance on it as a trading partner.

Not so fast. Interdependence works both ways. We rise or fall together. And I would prefer that we rise. Why not, as C. Fred Bergsten, director of the Peterson Institute for International Economics, has suggested, look to the dynamic economies of China and India to help lift the United States out of its economic troubles?

The Economist, in its annual forecast for 2008, aptly echoed that sentiment: “Crudely put, the fate of the American economy [this year] will be determined by three F-words: foreclosures, foreigners and the Fed.” While acknowledging the severity of the housing crisis, the forecast advised that recession is not a certainty due to two counterweights: monetary policy, which will produce more interest-rate cuts, and a likely continuing boom in American exports.

Throw in a sensible U.S. economic-stimulus package, and optimism should rise. There is no point in anticipating or dooming ourselves to the worst before we try our best.

Most importantly, global thinking and considerations must infuse solutions to economic uncertainty and other challenges. Today, and for the foreseeable future, this message is worth repeating:

It’s foreign policy, stupid.