Fascinating article from The Economist....
Can software really predict the outcome of an armed conflict, just as it can predict the course of the weather?
IN DECEMBER 1990, 35 days before the outbreak of the Gulf war, an unassuming retired colonel appeared before the Armed Services Committee of America's House of Representatives and made a startling prediction. The Pentagon's casualty projections—that 20,000 to 30,000 coalition soldiers would be killed in the first two weeks of combat against the Iraqi army—were, he declared, completely wrong. Casualties would, he said, still be less than 6,000 after a month of hostilities. Military officials had also projected that the war would take at least six months, including several months of fighting on the ground. That estimate was also wide of the mark, said the former colonel. The conflict would last less than two months, with the ground war taking just 10 to 14 days.
Operation Desert Storm began on January 17th with an aerial bombardment. President George Bush senior declared victory 43 days later. Fewer than 1,400 coalition troops had been killed or wounded, and the ground-war phase had lasted five days. The forecaster, a military historian called Trevor Dupuy, had been strikingly accurate. How had he managed to outperform the Pentagon itself in predicting the outcome of the conflict?
His secret weapon was a piece of software called the Tactical Numerical Deterministic Model, or TNDM, designed by the Dupuy Institute, an unusual military think-tank based near Washington, DC. It was the result of collaboration between computer programmers, mathematicians, weapons experts, military historians, retired generals and combat veterans. But was the result a fluke, or was the TNDM always so accurate?
Bosnia was its next big test. In November 1995, General Wesley Clark asked the Dupuy Institute to project casualty scenarios for NATO's impending peacekeeping mission, Operation Joint Endeavour. The resulting “Bosnia Casualty Estimate Study”, prepared using results from the TNDM, stated that there was a 50% chance that no more than 17 peacekeepers would be killed in the first year. A year later, six had died—and the Dupuy Institute's reputation had been established.
The TNDM's predictive power is due in large part to the mountain of data on which it draws, thought to be the largest historical combat database in the world. The Dupuy Institute's researchers comb military archives worldwide, painstakingly assembling statistics which reveal cause-and-effect relationships, such as the influence of rainfall on the rate of rifle breakdowns during the Battle of the Ardennes, or the percentage of Iraqi soldiers killed in a unit before the survivors in that unit surrendered during the Gulf war.
Analysts then take a real battle or campaign and write equations linking causes (say, appropriateness of uniform camouflage) to effects (sniper kill ratios). These equations are then tested against the historical figures in the database, making it possible to identify relationships between the circumstances of an engagement and its outcome, says Chris Lawrence, the Dupuy Institute's director since its founder's death in 1995.
All of this is akin to working out the physical laws that govern the behaviour of the atmosphere, which can then be used in weather forecasting. But understanding the general behaviour of weather systems is not enough: weather forecasting also depends on detailed meteorological measurements that describe the initial conditions. The same is true of the TNDM. To model a specific conflict, analysts enter a vast number of combat factors, including data on such disparate variables as foliage, muzzle velocities, dimensions of fordable and unfordable rivers, armour resistance, length and vulnerabilities of supply lines, tank positions, reliability of weapons and density of targets. These initial conditions are then fed into the mathematical model, and the result is a three-page report containing predictions of personnel and equipment losses, prisoner-of-war capture rates, and gains and losses of terrain.
What is perhaps even more surprising than the TNDM's predictive accuracy is the fact that it is for sale. The $93,000 purchase price includes instruction classes, a year of technical support and a subscription to the TNDM newsletter, although subsequent updates to the software cost extra. Organisations that have acknowledged buying the software include the defence ministries of Sweden, South Africa, Finland, Switzerland and South Korea, along with the aerospace giant Boeing. Such customers rarely divulge the uses to which they put the software. But Niklas Zetterling, formerly a senior researcher at the Swedish National Defence Research Institute in Stockholm and now an academic at the Swedish War College, says his country uses the software to improve its arsenal. Mr Zetterling toyed with the software's technical variables “to create hypothetical weapons” that could then be proposed to engineers.
Rather than simply buying the TNDM, most clients contract the Dupuy Institute to produce studies that combine the software's predictions with human analysis. American clients have included the Joint Chiefs of Staff, the Army Medical Department, the Department of Defence, the Vietnam Veterans of America Foundation and the Sandia National Laboratories (a government-owned weapons-research centre run by Lockheed Martin). The institute is currently preparing a secret forecast of the duration and intensity of the Iraqi insurgency for the Centre for Army Analysis, a Pentagon agency.
Leader of the pack
The TNDM is not the only war-forecasting system. Many other systems have been developed, primarily by armed forces, government agencies and defence contractors in America, Australia, Britain, France and Germany. Some are glorified spreadsheets, but many are far more complex, including the American Navy's GCAM software, the OneSAF model used by the Army and Marine Corps, the Air Force's BRAWLER system and the Australian Department of Defence's JICM. With all these systems, younger officers tend to have more faith in the technology than their older counterparts. (According to a joke among technophiles, old-school military planners refuse to upgrade from BOGSAT, or “Bunch of Guys Sitting Around a Table”.)
A survey of American war-forecasting systems by the Dupuy Institute found that very few are for sale or hire, and officials in charge of government models are often unwilling to share them with rival agencies. The simple availability of the TNDM has favoured its growth, although technology-transfer laws not surprisingly restrict its sale to certain countries.
Another attraction of the TNDM over rival models is the Dupuy Institute's independence: it has no weapons to sell, is not involved in internecine competition for budgetary funding, and has no political stake in military outcomes. Software developed primarily for, or by, a contractor or a branch of the armed forces often favours certain hardware or strategies, says Manfred Braitinger, head of forecasting software at IABG, a Munich-based firm that is Germany's leading developer of war-forecasting systems. The Air Force and Army models differ widely, for example, in their estimates of how easy it is to shoot down planes. “If you run both models you will see a remarkable difference in attrition rates simulating the same scenario,” Mr Braitinger says. Systems with a wide customer base, like the TNDM, are regarded as more credible, since they do not have such biases.
The TNDM's reliance on real combat data, rather than results from war games or exercises, also gives it an edge. Another forecasting system, TACWAR, was used by America's Joint Chiefs of Staff to plan the overthrow of Saddam Hussein. Like many models, it was largely developed with data from war games. As a result, says Richard Anderson, a tank specialist at the Dupuy Institute, TACWAR and other programs based on “laser tag” exercises tend to “run hot”, or overestimate casualties. Real-bullet data is more reliable, because fear of death makes soldiers more conservative in actual combat than they are in exercises, resulting in fewer losses. The discipline is only just beginning to recognise the “tremendous value of real-world verification”, says Andreas Tolk, an eminent modelling scientist at Virginia's Old Dominion University.
Yet another factor that distinguishes the TNDM from other war-forecasting systems is its unusual ability to take intangible factors into account. During NATO's air campaign above Serbia and Kosovo in 1999, for example, the Serbs built decoy tanks out of wood and tarpaulins and painted trompe l'oeil bomb-holes on to bridges. Microwave ovens, modified to operate with their doors open and emit radiation, were used as decoys to attract HARM missiles that home in on the radar emissions of anti-aircraft batteries.
Such cunning is one of the many intangible variables that are taken into account by the TNDM's number-crunching equations. Mr Lawrence says incorporating human factors into equations is controversial: most models favour “harder” numbers such as weapons data. But Robert Alexander, an expert on war simulations at SAIC, an American defence contractor, says these are “almost secondary” to human factors.
The Concepts Evaluation Model (CEM) developed at the Pentagon's Centre for Army Analysis, provides an instructive example. While testing the model, programmers entered historical data from the Battle of the Bulge, the German offensive in 1944 against American forces in Belgium. The CEM predicted heavy German losses in the initial attack, yet German casualties were in fact light. The probable error? The model overlooked the shock value of launching a surprise attack. Analysts duly recalibrated the CEM—using an early version of the TNDM.
The Dupuy Institute is renowned for its ability to take into account such non-material factors: the effect of air support on morale, fear engendered by attack with unexpected weaponry, courage boosted by adequate field hospitals. The mother of all intangibles, within the TNDM model, is initiative, or the ability of lower-ranking soldiers to improvise on the battlefield. Armies from democratic countries—where people are empowered to make decisions—benefit by giving their soldiers some scope to change tactics in the midst of a firefight. Soldiers fighting for authoritarian regimes may not have the reflexes, or the permission, to seize opportunities when they arise in battle.
Maintaining the accuracy of the TNDM means feeding it with a constant stream of new information. The Dupuy Institute's analysts visit past battlefields to augment their statistical data, follow the arms industry closely and cultivate contacts with government defence procurers. In countries where access to military archives is limited, the Institute surreptitiously pays a handful of clerks to provide photocopies.
The next challenge will be to expand the TNDM's ability to forecast the outcomes of “asymmetric” conflicts, such as the Iraqi insurgency. To this end, the Dupuy Institute is hoping to get its hands on the Vietcong archives, as Vietnam opens up. Insurgencies rarely leave much of a paper trail, but the Vietnamese kept detailed records of their struggle against the French and Americans. The resulting papers provide the world's most extensive documentation of guerrilla fighting. “That's where warfare seems to be heading,” says retired Major General Nicholas Krawciw, who is the president of the Dupuy Institute. And wherever warfare leads, war-forecasting systems must follow.
And now, the war forecast....
Moderator: Alyrium Denryle