AP Photo

The arrival of US marines in Darwin is a good thing. It provides a ready capability to respond to disaster and humanitarian crises throughout the Asia-Pacific region.

With their extensive experience in operating amphibious ships, marines can also assist Australia in developing the new Landing Helicopter Dock capability.

But there can be too much of a good thing, especially if it involves putting unnecessary pressure on China. By substantially increasing its close relationship with the US, Australia may unduly complicate its relationship with China. Care needs to be taken to ensure that Australia is not caught between the US, as security guarantor, and China as economic underwriter.

As a sovereign nation Australia should maintain the ability to say no to the US and...