On the night of March 21, 2003, and for two weeks thereafter, the largest barrage in history rained down on Baghdad, Iraq, with such precision that the lights stayed on.

Baghdad, like Hiroshima, marks a new era in warfare impelled by weapons that eclipse all others before them.The atomic bomb, or A-bomb, brought a quantum leap in the magnitude of indiscriminate annihilation.Today's geographically savvy weapons, let's call them collectively the geographic bomb, or G-Bomb, brought a quantum leap in the precision with which selective destruction can be administered anywhere on Earth.

Both changed the nature of warfare forever, and the G-Bomb - relatively cost-free in allied casualties and guilt-free in civilian casualties - will be employed far more freely than the A-bomb ever could.The implications, both good and bad, for foreign policy, international relations, and global ethics are staggering.

Back home, the same technology that guides a missile can monitor and control a child, spouse, employee, or slave.Hence, geofencing is now commonplace and society must contemplate geoslavery, a new form of human bondage characterized by location control via human-tracking devices.The implications, both good and bad, for social relations, human rights, privacy, and freedom are staggering.

Earth-changing forces are at play, and it's startling how little society seems to know or care.Following Baghdad's "shock and awe," there's been no prominent discussion of what the G-Bomb really is, much less what it's impacts will be.It's as if national leaders in 1945 had lauded the A-bomb without knowing or caring what lay behind it, and citizens had gawked at it's mushroom cloud without concern.

The simplistic explanation for precision bombing, trumpeted by national leaders and pundits alike, is GPS, but that's just one of many data streams flowing in a grand, global GIS that encompasses every battlefield.With GPS alone, a missile's guidance system couldn't distinguish Baghdad from Babylon, much less determine which buildings to hit, hills to dodge, and people to miss.As Robert McColl , professor emeritus of geography at the University of Kansas, once said, "If all you have is GPS, the best you can do is call fire in on yourself."

The G-Bomb demands GIS, a digital model of the earth that makes sense of all geographic information.It demands a system that faithfully records the precise three-dimensional geometry and descriptive attributes of all pertinent physical and cultural features (elevation, buildings, land cover, population, satellite imagery, boundaries, plus GPS-derived latitude/longitude coordinates of troops in the field and missiles in flight).It must keep track of highly complex spatial relationships among features.It must have the unique functionality of GIS to model, analyze, and display all features that occupy geographic space.

How, for instance, do troops know where not to shoot in order to avoid civilian casualties? It's one thing to know where each bomb will fall, and GPS can tell you that.It's quite another to know where the people are, and that requires a GIS.And make no mistake, avoiding civilian casualties is paramount in defense policy today.As one Pentagon officer said, "There are no single targets that are war winners, but many targets are war losers."

My contribution was the population database.From 1997 through 2001 at Oak Ridge National Laboratory (ORNL), I led the team that developed the LandScan Global Population Database (30 arc seconds resolution), the most precise population database ever developed for the entire earth.After moving to KU the University of Kansas in 2001, I continued to refine population data down to building and block level.As horrifying as the fighting was in Iraq, I woke each morning knowing, at least, that our work had saved lives compared to what would have happened otherwise.

LandScan is a prime example of how GIS data funded for one purpose can have many other beneficial uses.After the Asian Tsunami of 2004, tThe New York Times, National Public Radio, and other news media reported that LandScan proved to be the only feasible means of identifying and estimating impacted populations in the narrow coastal strips devastated by the wave.My colleagues at ORNL - Eddie Bright, Phil Coleman, and Budhendra Badhuri - are justly proud of their work in that far-reaching catastrophe.They continue to update and improve LandScan annually, and you can get it free from their website.

What science underlies the A-bomb? In 1945, everybody knew it was physics, and physicists became the darlings of science.Imagine what would have happened if no one had known.There would have been no federal "NDEA" loans to further science and mathematics, no federal programs to promote beneficial uses, and no intelligent safeguards.

What science underlies the G-bomb? Today, hardly anyone seems to know that geography had a hand in it.Most of society is still caught up in the silly notion of geography as "learning your states and capitals" that arose after World War II.There is, in fact, no greater gulf in knowledge today than that between the public image of geography and the reality of what geographers actually do.

Geographers do not "own" the GIS movement, but they have been prominent leaders, developers, and practitioners from its inception to the present.For thousands of years, geographers, cartographers, geodesists, and surveyors advanced the science that made GIS possible. In the last century, remote- sensing specialists, landscape architects, spatial statisticians, computer scientists, and topologists joined them.Geography is the "G" in GIS and the intellectual home of GIS, as it was already the intellectual home of cartography and other geographic sciences.Geographers may differ in many ways, but all agree their venerable discipline, like GIS, is defined not by its subject matter but by its emphasis on spatial analysis, place-based science, and integration.

Popular misconceptions about geography and simplistic conceptions of GIS continue to hamper public awareness and debate.But, as Ambrose Bierce (1842-1914) said, "War is God's way of teaching Americans geography." The newest lesson is that GIS unleashes the power that traditional geography always had.Now, an informed public must vigorously guide politicians, geographers, and others on ethical bounds for a discipline that suddenly has joined physics and chemistry among the most beneficial and most dangerous of sciences.Course corrections in foreign and domestic policy, science, and education are essential.They must be as sweeping as those of the nuclear age, and they must begin now.The dawning of the A-bomb brought on a "nuclear age" characterized by enormous public investments in education, production, and safeguards.Will the dawning of the G-bomb bring on a new "geographic age?" Heaven help us if it doesn't.