Publicly, US President Barack Obama and senior officials in his administration berated North Korean leader Kim Jong-il recently for firing 11 ballistic missiles eastwards, into the Sea of Japan - four short-range missiles on July 2 and seven medium-range missiles on July 4. It was the biggest North Korean missile barrage seen so far.
Secretly, US officials informed on missile defences were pleased, for two reasons. First, the elaborate US missile defence in place in Japan, Alaska, California, Hawaii, aboard navy ships, and in satellites was severely tested and worked well. In particular, the fusion of data from sensors based on land, at sea and in space produced swift, clear images of what the missiles were doing.
Second, US intelligence gathered information about the missiles that otherwise could not have been discovered. 'We learned an incredible amount about where exactly North Korea is in their long-range missile development programme,' said an official in Washington. As North Korea has only ageing radar, he doubted it 'learned anything close to what we learned about their tests'.
The officials said North Korea's missiles were fired from mobile launchers but the US had been able to track them with satellites and reconnaissance aircraft.
In addition, the North Koreans have become more skilled at disguising launch sites with shields like medieval armour through which radar cannot see. The US, however, has found undisclosed ways of piercing that camouflage.
The missiles were sighted by US radar in northwestern Japan near the remote village of Shariki, then picked up by radar on Shemya in the Aleutian chain of Alaska and another encased in what looks like a giant golf ball aboard a seagoing base in the mid-Pacific. A satellite and an Aegis destroyer on patrol in the Pacific also tracked the missiles.
