The militaries of the United States and the Republic of Korea are accelerating installation of the controversial Terminal High Altitude Area Defense anti-missile system south of Seoul.

If, as US Pacific Command chief Harry Harris claimed, THAAD is expected to be operational "in the coming days", there is little chance of it being suspended because of protests from Beijing and Moscow, even though it comes at a time when Washington and its allies want them to commit more comprehensively and deeply to coordinated moves.

Although the official excuse has been Pyongyang's wayward stuntsmanship and the threat it poses, making THAAD a fait accompli and pre-empting any change of mind from the next administration in Seoul may be a more powerful driver behind the rush to get THAAD up and running in the ROK.