Fleet entry into Sydney Harbour, 1913

A hundred years ago, the Royal Australian Navy's first fighting fleet steamed into Sydney Harbour. In recent days the city has hosted several huge events to mark that centenary — an international fleet review, a fireworks spectacular, and a conference with some of the big guns from the world of maritime strategic thought.

But beyond the dazzle and the protocol, what's it all about? This is not a naval celebration for its own sake. There are some important policy agendas at work.

Looking outwards, this is a moment for defence diplomacy. Navies are the most diplomatically useful of all armed services — a ship visit looks less intrusive than boots on the ground. And, amid the Indo-Pacific region's current phase of armaments acquisition, assertiveness and strategic anxiety, every chance for positive engagement by navies is worthwhile.

The fleet review was preceded by an unprecedented multilateral exercise involving naval units from all of Asia's major powers (The Interpreter will publish a insider's assessment of that exercise in coming days). In addition, the present Sea Power Conference involves a forum of regional navy chiefs. That is good practice for Australia's hosting next year of the Indian Ocean Naval Symposium.

In a show of transparency, many of the 18 visiting warships, though not the Chinese destroyer Qingdao, have hosted open days.

Another purpose of all this choreographed naval gazing, though, is domestic, or it should be: reminding the Australian people, and the nation's new government, that this nation's strategic environment is deeply maritime. The navy matters now at least as much as it did a century ago.

With the 1915 centenary of ANZAC shortly to compel Australians' attention towards the myth, past, present and future of this sea-girt nation's army, it is convenient and sensible that the navy has seized the chance to get in early and mark its own place in the national consciousness.

Of course, this is no crude contest between the services: today's Australian army recognises that the nation's economic and security interests are maritime, and is defining its future relevance as part of a joint force prosecuting a maritime strategy. The Chief of Army said as much at the Sea Power conference yesterday.

Instead, the challenge for the Australian Defence Force may not be so much about how to share the budget pie as about whether it will be anywhere as big as it needs to be to give the nation credible strategic weight in a more uncertain and contested Indo-Pacific Asia. That's an issue my colleague James Brown and I will address in a Lowy Institute Analysis to be released later this week; here's a curtain-raiser

Image courtesy of the Royal Australian Navy.