There are 2 alliances against China. The Quad, consisting of Japan, India, Australia and the US. This is an immensely regional powerful coalition with multiples of China’s population, land area and GNP. Two coalition members, India and Japan, are in current territorial conflict with China.
AUKUS consists of a coalition not directly in conflict with China, but in strategic rivalry. The US, UK, Australia. They are competing for global leadership of planet earth.
The UK plays an outsize historical role in this. “Global Britain” declared economic independence from Europe with Brexit. AUKUS is in a sense the military equivalent. It’s almost as if an Anglo superstate is being born.
The nascent Anglo supercoalition is both sea and spacefaring. It’s a classic matchup between a land power and seapower. The maritime power will avoid, at all costs, a large ‘land war in Eurasia’ and will focus on controlling the commons: the sea, space and cyberspace.