The shadowy outlines of a two-ton gorilla sitting in the corner began to become visible for an instant to some attending the monthly luncheon of the Falls Church Chamber of Commerce Tuesday.

John McClain, senior fellow at George Mason University’s renowned Center for Regional Analysis, suggested with some prodding from the audience that Northern Virginia leaders might be “behind the curve” in planning for the region’s future, because they’ve not yet lined up the next driver of its economy once the war in Iraq winds down, and the billions in outsourced defense contracts here dry up.

As if it is not bad enough already that the global economic crisis and expected protracted slowdown will bring tough times to this region, though not as acutely compared to other areas, because of the stabilizing role of government employment here. But the advantage of Northern Virginia is also dependent on a continuation of the high level of government contracts being awarded to defense-related businesses here, which has fueled a boom from 2002 to the present.

Two things threaten this advantage, as McClain put it. First, there is the end of the Iraq war. Second, there is the prospect of a new “philosophy,” as he put it, of government that could eschew the last 28 years’ trend toward outsourcing of government functions, altogether.

What will be the region’s next economic driver? Will it be green technology? Will it be biomedicine? McClain asked some rhetorical questions, and said that regional leaders, including political, business and academic types, will have to put their heads together and come up with a plan. But then it was asked, “What is the likelihood that Northern Virginia is already behind the curve in this, given the competition for these kinds of drivers coming from other parts of the country?” McClain conceded that the region, indeed, might already be at a relative disadvantage on this score.

If true, so much for all the plans of the Tysons Corner Task Force for all that commercial and residential density in the coming decades. New realities, including a new administration in Washington, may change the economic climate here in a big hurry.

The region will continue to be attractive because of its proximity to the center of the federal government, and because of the distinctively pro-business posture of Virginia. But these factors alone do not suffice to fill the office space and residences already here, much less planned, without an economic driver. Presuming they’re all elected next month, Mark Warner, Gerry Connolly and Jim Moran are going to have their hands full not only getting funding for rail to Dulles, but for keeping the economic engine stoked with federal dollars in this region. It’s work that should have begun yesterday.