June 9, 2012:
For most of the last two decades the biggest importers of weapons were China and the Persian Gulf Arab states. But in the last few years that has been changing. India has become the biggest importer, followed closely by South Korea and Pakistan. China is still a heavy buyer but so is tiny Singapore. India imports about ten percent of arms exports, twice as much as China.
The shifts are all about money and self-sufficiency. After the Cold War ended in 1991, China became a major buyer of Russian weapons and stealer of Russian weapons technology. Although China licensed some Russian tech, they stole a lot more. Largely as a result of that Russia began turning down Chinese orders five years ago. At the same time China kept getting better at copying Russian weapons designs. China is aiming for near-total self-sufficiency in weapons but there will always be some new stuff out there they will seek to buy and copy. China has also become one of the major exporters of weapons.
India has been doing the same thing as China, only India doesn't steal, and has been much slower to acquire advanced manufacturing techniques needed to produce the most modern weapons. Until the 1990s, India had more modern weapons and military equipment than China. Over the last two decades China has caught up and passed India. One result of that is China becoming more aggressive in pressing for resolution, on Chinese terms, of old border disputes with India. This has caused India to import more modern arms and try harder to become more self-sufficient in weapons design and production. This has proved very difficult because India long ago set up a bureaucracy (DRDO or Defense Research and Development Organization) to do just that. But DRDO became a monumental example of bureaucratic inefficiency, wasting billions of dollars and decades of effort on weapons systems that never quite became operational (or when they did, they really weren't).
South Korea, on the other hand, spent the last two decades letting private firms develop new weapons (often using purchased or licensed foreign tech). American technology was imported to help build new armored vehicle and warship designs. Russian tech was obtained for new missile designs. But at the same time South Korea also imported a lot of modern weapons, to put it on a par with Japanese (now a close ally), ahead of China, and way ahead of North Korea (which constantly threatens to invade again).
The Gulf States are still big importers but most of these countries, especially Saudi Arabia and the UAE, are still digesting big acquisitions they made over the last decade.