Rocket success shows North Korea's advance

North Korea appears to have turned a corner in its goal of achieving mastery of ballistic missiles. 

This is the view of US officials and weapons experts after Pyongyang's successful rocket launch. 

A particular concern for US officials is that Iran could take heart from its Asian ally's success and accelerate what the West suspects is a goal of developing a warhead. 

Pyongyang and Tehran have closely cooperated in developing missile systems for more than 20 years. 

The UN Security Council condemned the North's launch yesterday of a three-stage rocket that Pyongyang claimed had placed a weather satellite into orbit. 

The launch appeared to be the country's first breakthrough following four largely unsuccessful tries since 1998.