LONDON, Aug. 2 -- It's now nearly four years since the trilateral security pact between Australia, the United Kingdom, and the United States, known as AUKUS, was announced to a great fanfare. The fundamental principle of the pact is to strengthen defence ties between the three nations and in doing so enhance security in the Indo-Pacific region. The three countries already had a history of military and intelligence cooperation as members of the "five eyes". But rising tensions in the Indo-Pacific resulting from China's expansive territorial claims in the South China Sea, its military modernisation and growing economic and military clout prompted the three nations to look for new ways to bolster security in the region.

The centrepiece of t...