An Australian Broadcasting Corporation look at the strategic move of sending in the Marines to the Northern Territory.

A continuation of a 60 year alliance and a message:

ALAN DUPONT, INT. SECURITY STUDIES, UNSW: It’s not so much the Marines themselves but it’s the symbol – the signal it sends to the region that Australia is – and the United States are working together to meet these common challenges. So I think it’s quite an important shift.

UPDATE: Robert Kaplan has a related analysis at Stratfor America’s Pacific Logic:

Were the United States not now to turn to the Indo-Pacific, it would risk a multipolar military order arising up alongside an already existent multipolar economic and political order. Multipolar military systems are more unstable than unipolar and bipolar ones because there are more points of interactions and thus more opportunities for miscalculations, as each country seeks to readjust the balance of power in its own favor. U.S. military power in the Indo-Pacific is needed not only to manage the peaceful rise of China but also to stabilize a region witnessing the growth of indigenous civil-military post-industrial complexes.