March 7, 2011: A year after first equipping its Merkava tanks with APS (Active Protection System), for defense against missiles and RPGs, one of these tanks successfully used its APS to defeat an RPG attack. The crew didn't realize this until after it was over. That, however, is how APS is supposed to work.

This first combat use is a big deal, because APS has been around for nearly three decades, but demand, and sales, have been slow. The Israeli Trophy APS uses better, more reliable, and more expensive technology than the original Russian Drozd (or its successors, like Arena) APS. For about $300,000 per system, Trophy will protect a vehicle from ATGMs (Anti-Tank Guided Missiles) as well as RPGs (which are much more common in combat zones.) Israel is the first Western nation to have a lot of their tanks shot up by modern ATGMs, and apparently fears the situation will only get worse. Israel first encountered ATGMs, on a large scale, in the 1973 Arab-Israeli war. But these were the clumsy, first generation missiles that turned out to be more smoke than fire. More recent ATGM designs have proved more reliable and effective, but no nation, except Israel, has yet made a major commitment to APS. That may now change, simply because one RPG got shot down.

Meanwhile, new APS systems continue to appear. Last year, a Ukrainian firm developed a new APS called Zaslon. This one  is a cross between the APS that use small missiles, and those that use ERA (Explosive Reactive Armor, blocks of explosive that go off when hit by an anti-tank shell or missile). Zaslon uses explosives to hit RPG rockets or missiles, a meter or so from the target vehicle. Over the last five years, U.S. Army officers have been impressed with demonstrations of the Zaslon technology, but now the Zaslon system is ready for the market.

It's a crowded and uncertain market. Most APS consist of a radar to detect incoming missiles, and small rockets to rush out and disable the incoming threat. A complete system weighs about a ton. Russia pioneered the development of these anti-missile systems. The first one, the Drozd, entered active service in 1983, mainly for defense against American ATGMs. These the Russians feared a great deal, as American troops had a lot of them, and the Russians knew these missiles (like TOW) worked. Russia went on to improve their anti-missile systems, but was never able to export many of them. This was largely because these systems were expensive (over $100,000 per vehicle), no one trusted Russian hi-tech that much, and new tanks, like the American M-1, were seen as a bigger threat than ATGMs.