Hiroyuki Akita, Nikkei commentator

TOKYO — The Solomon Islands, strategically located in a small part of the South Pacific, has severed ties with Taiwan in favor of relations with China. Taiwan’s diplomatic isolation increased on Friday after the Pacific island nation of Kiribati also cut official ties with the self-ruled island amid mounting Chinese pressure on nations to abandon Taiwan.

After the loss of the Solomons and Kiribati, the number of countries with which Taiwan has diplomatic relations now stands at only 15, further diminishing Taipei’s presence on the international stage.

But the Solomon Islands was the biggest of the six countries with which Taiwan still had ties in the Asia-Pacific region.

The Solomons Islands’ new diplomatic reality has implications beyond the immediate neighborhood. Situated some 1,750 km northeast of Cairns, in northern Australia, the nation joins Papua New Guinea, Vanuatu, Fiji and Tonga — which lie on an axis with the Solomons and already have official ties with Beijing — in tying the diplomatic knot with China. The countries have drawn steadily nearer to China, thanks to Beijing’s ample aid.

With the Solomon Islands and Kiribati in China’s orbit, Australia’s access to the Asia-Pacific region is geographically impeded by a pro-Beijing bloc. This predicament is not helped by Indonesia to the north, another country that has close economic ties with China.

The latest diplomatic reshuffling is not some random set of occurrences, but rather a deliberate tactic by Beijing to form a “great wall” to the north and west of Australia. In Vanuatu, China is constructing a large seaport, with observers speculating that the facility will be used as a military base. Last year, China provided Fiji with warships, while in Papua New Guinea, a port and roads are under construction with Chinese support.

Curiously, China’s moves in the South Pacific mirror somewhat the strategy of the Japanese military during World War II, which tried to block Australia’s sea routes to the U.S. and keep the Americans from establishing bases in the country. Doing so would deprive the U.S. of a much-needed foothold in the region while expanding Japan’s sphere of influence.

In fact, Japan occupied the port town of Rabaul in what is today’s Papua New Guinea, making it the base for its southern operations. To further hamper Australia-U.S. supply and communication lines, Japan also planned to capture Fiji and Samoa. The plan was eventually abandoned, after which Japan built an air station on Guadalcanal Island in the Solomons, with the aim of using the base as a springboard for conquering Australia and the South Pacific. The fierce battle between Japan and U.S.-led Allied forces on Guadalcanal is testament to the island’s importance — then and now.

Obviously, China is not advancing into the South Pacific to wage war against the Americans. Still, forging cozy relations with countries near the perimeter of Australia makes it easier for China to gain a geopolitical advantage over the U.S.

Australian authorities have outlined a scenario that has caused considerable consternation in Canberra. In it, China builds military-capable seaports and airports across the South Pacific, covering the region with a radar network that could not only monitor U.S. and Australian forces, but also allow Beijing to needle Washington and Canberra with frequent visits by Chinese warships.

Furthermore, an increase in the number military-capable facilities open to China will allow Beijing to formulate detailed operational plans to deal with any eventual crisis, the Australian authorities added.

Meanwhile, the U.S. began in 2012 rotational deployment of troops to Darwin to counter China’s military adventures in the Asia-Pacific region, with more than 2,000 U.S. Marines already stationed in the city.

It is this presence of U.S. troops in Australia that may be pushing China to construct its “great wall of islands.”

The Solomon Islands and Kiribati tend to be regarded as just sleepy outposts in the the South Pacific. But the countries’ decision to move closer to Beijing could have major repercussions in the future as the strategic maneuverings of America and China in the region play out.