India, using some of the Israeli sensor technology, erected a 580 kilometer electrified fence along the Line of Control (LOC) in Kashmir. In 2004, India bought more radars, and special jamming equipment (to shut down radios used by Islamic radicals trying to cross the border) for use in Kashmir and along the LOC. The use of ground radars, thermal imaging and other electronic gear along the LOC, reduced illegal movements into Indian controlled Kashmir. But the Islamic radicals keep coming, although in much reduced numbers. In 2001, it was estimated that 2,417 Islamic terrorists got across from Pakistan (where the government tolerates the terrorist training camps) to Indian Kashmir (where the terrorists are trying to drive the Indians, and all non-Moslems, out of the region). In 2002, that went down to 1,504, in 2003 it was 1,373 and in 2004 if was 537. The earthquake in late October, 2005, wrecked portions of the fence system, so 597 terrorists got across in that year. In the first six months of 2006, only 189 got across. The infiltrators don't come empty handed, but haul large quantities of weapons, and cash. Hand grenades are the favorite terrorist weapon these days, and local Moslems are hired to toss them. It's relatively easy money ($10-20), because if you know your way around an area, you can toss the grenade and get away unseen.
The Kashmir terrorists spend most of their time terrorizing local Moslems (to cooperate, and not work with the police) and non-Moslems (to get them to leave). The terrorists operate in camps way up in the forested hills. While some generals have urged that a division size (10,000 or so troops) operation be launched to clear out these terrorist camps, such an undertaking is expensive in terms of money and casualties. Besides, there are only 50-80 terrorists up in those camps at any one time, and that small a number of people could, for the most part, escape an army sweep operation. There are plenty of police in the populated areas (31,000 around the provincial capital alone) to capture or kill most of the Islamic terrorists that show up.
It's gotten easier lately, to catch terrorists in Kashmir, because the majority Moslem population is tired of nearly two decades of violence, without much to show for it. So more Moslems are becoming informants for the police. That, plus the spread of cell phone systems, makes it easier for these informants to tip off the police when Islamic terrorists are in the are. The terrorists are trying to get people to give up their cell phones, but that has not been very popular.
The Islamic terrorists have found weaknesses in the security fence system, and the Indians must constantly tweak their sensors and security system design to keep up. In one terrorist camp back in Pakistan, a stretch of the Indian fence has been reconstructed, so the terrorists can develop news ways to safely breach it. India would like to get these camps shut down, but Islamic conservatives are a major political force in Pakistan, and the government risks a lot of unrest if the terrorist camps are trifled with. However, Pakistan and India have had a cease fire since late 2003, which has halted the assistance the Pakistani army used to provide for the terrorists. This included shelling portions of the fence, to knock out sensors, or prevent the Indians from making repairs. Without that kind of interference, it appears that India may be able to eventually reduce the number of infiltrators to a less than one a day.
For a long time, it was conventional wisdom that you could not prevent irregulars (terrorists, guerillas, bandits, smugglers), from getting across a long frontier. Apparently the conventional wisdom is wrong. Both Israel and Pakistan have been able to build security fences that have succeeded in keeping terrorists out. The Israeli security will eventually be 760 kilometers long. But even with only half of it completed (and blocking the most used terrorist crossings), the Palestinian terror campaign collapsed.