Foreign Minister Julie Bishop is in Tokyo today, but the real landmine in Australia’s regional defence relationships is not likely to be publicly discussed.

What the minister knows, but is not widely understood, is that while last year’s defence White Paper publicly dodged anything controversial to avoid upsetting China, Australia has quietly been training soldiers for two of China’s main regional adversaries, Vietnam and the Philippines.

Crikey can reveal that in the past five years Australia has trained close to 1000 military personnel from these two countries. China has been aggressively pressuring both in its breathtaking claim for most of the South and East China Seas.

Along with Prime Minister Tony Abbott’s very public and fresh embrace of Japan last week as Australia’s “best friend” in the region, Bishop may have some explaining to do when she gets to Beijing on October 23.

While trade has been the focus for the Abbott government’s diplomatic efforts, defence is under-appreciated. China’s rapidly modernising military has triggered a regional arms race. It is no mistake that Bishop has deliberately chosen Japan, which she has described as Australia’s closest ally in North Asia, as her first stop on this four-country trip.

Australia’s defence relationship with China’s bete noire, Japan is extremely close; witness the tripartite foreign minister talks in Bali two weeks ago between Bishop and her Japanese and American counterparts Fumino Kishida and John Kerry. The allies issued a statement saying they opposed “coercive or unilateral actions” that could change the status quo in the East China Sea.

The Chinese government hit back immediately. “The United States, Japan and Australia are allies but this should not become an excuse to interfere in territorial disputes, otherwise it will only make the problems more complicated and harm the interests of all parties,” Chinese Foreign Ministry spokeswoman Hua Chunying said.

China is in dispute with Japan over islands in the East China Sea. China is also in dispute with another seven countries — including Taiwan — over parts of the South China Sea. The claims centre on rocky, generally uninhabited islands that lie over what is believed to be huge deposits of oil and gas.

“Like it or not, there is a regional arms race underway. Australia is quietly playing its own part, a part that is going to require very delicate diplomacy with China.”

And Australia is helping to train forces that in the worst case scenario would fight China if any of these disputes escalate.

“Australia offers between 120 and 160 training places in Australia per year to the Philippines. Since 2007, around 600 Filipino armed forces personnel have been trained in Australia,” the Department of Defence told Crikey in September. “Our defence relationship is focused on education and training, maritime security and counter-terrorism.”

Similarly, Australia’s defence engagement with Vietnam — established in 1998 — is “strong and continues to grow at a steady pace,” the Defence spokesman said. “Our defence engagement focuses on officer training and education … Australia offers around 80-100 training places per year to Vietnam. Since 2007, Australia has trained around 390 Vietnamese military personnel in Australia.”

At the top of the regional heap is Japan, a long-time US and Australian ally, whose age-old conflict with China has surfaced in recent years over the contested islands in the East China Sea, called the Senkaku islands by the Japanese and the Daioyu Islands by China.

Abbott has effectively backed Japanese Prime Minister Shinzo Abe’s stated aim to wind back the country’s anti-military post-war constitution and become, as Abbott said, a “normal” country.

Talk to any diplomat in the region and they will tell you that this potential conflict is top of mind for everyone outside China’s immediate sphere of influence. Last month Japan launched what, for all intents and purposes, was its first aircraft carrier since its de-militarisation after World War Two. The new carrier can deploy more helicopters than those in service in the navies of Italy and France, and is capable of being adapted for aircraft.

Abbott has made a substantial down payment on his promise to pull focus on Australia’s closest neighbours in Asia. There has been much talk of Australia’s “need to choose” between its biggest market, China, which takes a staggering 30% of our exports, and its primary military ally, the US. Australia has agreed to host US troops — including combat-ready marines based in Darwin.

The reality for Abbott’s team is complex. Like it or not, there is a regional arms race underway. Australia is quietly playing its own part, a part that is going to require very delicate diplomacy with China.

The move to station US troops in Darwin had bilateral support in the Australian Parliament. There are 250 this year, 1000 in 2014, and 2500 by 2017. China has taken sharp exception to this behind closed doors with Australian diplomats and politicians.

But Abbott, Bishop and Defence Minister David Johnston may need to focus on more immediate issues that could irritate Beijing. The Australian military has scheduled special forces and maritime exercises with the Philippines for the last quarter of 2013, and in the same three months biannual live fire exercises with Vietnam are planned. And while it is yet to be confirmed, the major Dawn Samurai exercise with Japan has been pencilled in for December.

None of these training programs or joint exercises have been aimed specifically against China, but in the event of any conflict between China and Australia’s allies in the region there is little doubt where Australia’s energies are being directed.

*Michael Sainsbury is a contributing writer to Nikkei Asian Review