The prologue of Rebalancing US Forces, a new book edited by US Naval War College professors Carnes Lord and Andrew Erickson, opens with Barack Obama's speech in to the Australian parliament on 17 November 2011. That single clue should alert Australian readers to their country's importance in America's Pacific policy.

There are a staggering 660 American overseas military sites in 38 foreign countries, so why is Australia highlighted? Lord and Erickson's essay collection will be a must-read for the entire Asian security establishment. But any Australian layperson interested in current affairs should read Rebalancing and ponder its meaning. For despite questions about America's staying power and reliability, Rebalancing's contributors describe in gritty detail a decisive, deliberate shift of US attention to the region. 

Contemporary US strategy in Asia is informed by history (for an excellent Australian perspective on facing a north Asian threat see here). The US military wants never to be caught off-guard again, like it was in 1941. And having fought two proxy wars against the PRC, in Korea and Vietnam, as one congressman in 1996 warned: 'you'd sure as hell better not get us into a war with the Chinese', at least an Asian land war.

Terrorism and North Korea are mentioned, but Rebalancing really is ABC — all 'bout China. The US has constructed a tripwire fence of 'forward presence' around China. Bases represent red lines (real ones, not hollow words like in Syria) which reassure allies but also invite hostility and possibly surprise aggression. It is the dilemma of danger, to be both threatening and vulnerable.

Guam is thought so strategically important that it might even tempt a pre-emptive nuclear strike by China. Japan's US bases (replacement value: US$45 billion) invite similarly enthusiastic assessments of 'coercion by missile' by PLA Second Artillery Force officers. American forces in Korea are similarly at risk, and Rebalancing reminds us that in the late 1970s presidential hopeful Jimmy Carter 'had called for the removal of all US ground forces from the peninsula.' Today the debate between Seoul and Washington over OPCON (wartime operational control) grinds on. 

Rebalancing considers the logistical challenges of maintaining a credible deterrent in the western Pacific and Indian Ocean theater, which covers twelve time zones. It is no wonder that Chinese strategists obsess over doctrines of supply disruption, and this is well covered in the book. It has fascinating details, for example about nuclear submarine reactor cores, warship steaming ranges and speeds, Australia's targeting role during during Desert Storm, the tempo of US personnel and materiel transiting Singapore every year (150 US ships, 400 aircraft and 30,000 personnel) and even the plumbing of Diego Garcia (not trivial given its average elevation of 4 feet above sea level).

The distance problem is actually worsened, not abated, by the higher speeds, longer ranges, greater mobility and accuracy of offensive weapons. It will be increasingly difficult for the US to maintain its presence in Asia while an adversary's systems hold it at bay. Some Chinese missiles can be launched off mobile launchers and therefore enjoy huge asymmetry against bases at a fixed address. The US will need to rotate its assets in a shell-game to make them more survivable — arithmetic versus geometry, as it were. There is even a chapter at the end on 'sea basing', an operational concept using floating mobile platforms for storage, repair and deployment.

Ultimately, though, Rebalancing is not about naval warfare; it is about bases, places and 'boots on the ground.' 

American boots are not always welcome, and the locals do usually get a vote. Rebalancing provides a sensitive acknowledgment of the frictions in alliances. Unsurprisingly Singapore is a solid, low key partner. By contrast, Australia comes across as a rather querulous ally. There is a long, rich history of tensions with Canberra over sovereignty, secret agreements, surveillance, and the sharing of information: plus ca change! Former prime minister Malcolm Fraser has recently argued that its American affiliation exposes Australia to unwanted entanglements, and potentially even attack. He has a point, but an independent Australia would realistically need to budget for defence spending at 4% or more of GDP and perhaps a military service program like Singapore, Sweden or Switzerland. I can't see this being popular. The default alternative is of course the American alliance and now basing (again) in Australia. Incidentally, did anyone consult Jakarta about those 2500 Marines to be based in Darwin? 

Rebalancing, by the authors' own admission, doesn't question what's in it for the US; a positive 'net assessment' of its forward presence is taken as self-evident. But the book does conclude that permanent American bases face greater risks and vulnerabilities, both physically and politically, than perhaps ever before.

There are a few other blanks in an otherwise superb collection. The Philippines is not addressed at all, yet this is the American treaty ally suffering the most glaring power asymmetry with China and with perhaps the most colorful Asian history of American basing. It's significant that China has asserted control of the Scarborough Shoal barely more than 100 clicks from Manila and Subic Bay, where US Navy ships visit with increasing frequency. Also, there is little mention of Taiwan. Of course an explicit US forward presence in Taiwan is out of the question, but the island is the elephant in the Asian military planning room. Rebalancing has an excellent chapter on Diego Garcia, and I think the editors should give the 'Indo-Pacific' geography greater emphasis. 

Finally, and perhaps outside the scope of this book, is the question of how forward locations are useful protection against modern asymmetric tactics: 'little green men', the prosecution of 'lawfare', and fishing boats and oil rigs doing salami slicing at sea. Are alliances still useful in this age of ambiguity and interdependence? Is America really prepared to stand up for its partners, when push comes to shove? Nothing, as Lord and Erickson imply, shouts commitment louder than bases.