At last the Pentagon seems to be getting close to unravelling the mystery of why tens of thousands of Gulf War veterans have fallen seriously sick, or died, since the conflict. It has nothing to do with the Iraqi bombs so feared at the time, but more likely a pill given by their own medics is to blame. 60 Minutes (World, 9pm) reports on the findings of a new report. The drug, pyridostigmine bromide, was supposed to protect them from Iraqi nerve gas. But a study underwritten by the Pentagon has concluded it may be responsible for the Gulf War Syndrome, symptoms of which include excruciating muscle and joint pain, headaches, chronic fatigue, memory loss and blackouts. The report contradicts earlier official claims that the drug had nothing to do with the syndrome. For years, possible explanations have been brushed aside. Officials at the Department of Defence, which funded the study, have accepted the latest findings but say more studies are needed, and they are keeping the drug in their arsenal. Another victim of warfare is featured in War Horse (National Geographic, 11pm), a two-part series on the history of horses in battle. This episode, The Iron Horse, focuses on the horse in the Middle Ages, when it became a central image in the code of chivalry. With the advent of the longbow in the 14th century, large, aggressive horses were bred to carry the huge weight of an armour-plated knight. Gunpowder made war an even more devastating experience for this innocent animal. Moroccan horsemen recall fast, wild cavalry attacks while the Mongols demonstrate raiding tactics used by Genghis Khan. Jamu: The Orphaned Leopard (National Geographic, 8pm) receives more kindly treatment from humans. The orphaned cub is rescued by John Varty in the Luangwa Valley, Zambia, and prepared for the wild. As a cub she makes friends with an orphaned warthog, a species which later on should be on her dinner menu. There are several claimants for the site of the dawn of the new millennium. A consortium of businessmen bought Chatham Island to profit from the occasion. But because the Earth spins on its axis at a tilt, little-known Gisborne on the far eastern tip of New Zealand is where they should have put their money. The question is whether Gisborne can cope. ATV reporter Gavin Walker went to find out for Inside Story (World, 6.55pm). The city is expecting 120,000 visitors, but it has only 3,000 hotel beds. The 40,000 local residents, though, are cashing in, many planning to camp on beaches and rent out their homes. The small city has had to overhaul its electricity supply and medical system and book 100 extra doctors. Meanwhile, the world waits to see whether Gisborne will be first to catch the Y2K computer bug.