U.S. President Donald Trump's most important strategic adviser on China right now could wind up being the late Douglas MacArthur.

Today China is pushing ahead with an aggressive strategy to dominate the so-called first and second island chains to China's east and south. MacArthur was the first to emphasize how crucial these were to restraining Communist Chinese aggression into the Pacific during the Cold War, and protecting America's own Pacific flank. China's ultimate goal is to push the U.S. out of the region, intimidate U.S. allies like Japan, and project Chinese maritime power as far east as Hawaii and Alaska.

Consequently, the Oceania region, a vast stretch of ocean with numerous island nations, including Papua New Guinea, Tonga, Vanuatu, Fiji and the Solomon Islands, has taken on an urgent new strategic importance.

China's aggressive effort to become the dominant power in the region has alarmed both Australia and Japan, which have both sought to prevent the tiny countries falling into Beijing's orbit.

The Australian government has significantly stepped up its aid packages to certain Pacific islands, many of which are struggling economically, and Tokyo has partnered with Canberra to increase its help.

The U.S., too, has a critical role to play in reversing the Chinese tide in the Pacific and maintaining the peace and stability that has prevailed in the region since World War II, when many Americans gave their lives after Washington had been slow to react to a similar challenge from Imperial Japan.

Pacific islands can serve as Chinese intelligence-gathering sites similar to those in the Spratly Islands in the South China Sea.   © DigitalGlobe/Getty Images

China's efforts to dominate the first island chain have drawn wide attention in recent years. Beijing's targets include not just Taiwan, a perennial Chinese concern. It is also contesting Japanese control of the Senkaku Islands and building up, and militarizing, islets to bolster its illegal claims to sovereignty over parts of the South China Sea.

Less noticed have been recent Chinese efforts in the second island chain, which stretches far into the central Pacific. Many of these islands were the scene of bloody fighting between the U.S. and Japan during World War II. 

China's strategy today ironically mirrors that of Tokyo in that era -- push back the U.S. and drive a wedge between Washington and its regional allies, which now include democratic Japan.

Today, of course, the struggle centers on economic and commercial competition, but with clear midterm implications for military and geopolitical advantages -- advantages that were evident to MacArthur nearly eight decades ago, and are to Beijing today.

Fourteen independent Pacific island countries lie within the second island chain. Extremely diverse in culture, language and political systems, they are united in feeling intense pressure from China to become part of its growing economic hegemony in Asia. Today China is the largest trading partner in the region. Beijing's total financial aid to the Pacific islands has grown to $5.9 billion since 2011.

A major focus of Chinese direct investment, some 70% in fact, has been Papua New Guinea. Given its growing dependence on Beijing, it is no surprise that the island nation was the first country to recognize China's claims to sovereignty in the South China Sea, even though a tribunal at the Permanent Court of Arbitration in The Hague would later, in 2016, rule those claims to be illegitimate. From a geopolitical perspective, gaining dominance over Papua New Guinea would position China to block Australia from sea lanes north to Japan and northeast to the U.S. 

Another Oceania nation that recognizes China's claims in both the South and East China seas is Vanuatu. At first the residents welcomed Chinese investment and trade to their tiny country, but the growing influx of Chinese workers and part-time residents triggered fears of a Chinese takeover, which were exacerbated by plans to establish two entire Chinese towns of 10,000 to 20,000 people each, while Vanuatus's capital has only 40,000 people. Now there are rumors that Beijing is pressing the government to consent to building a port that could be used for military purposes, not unlike the facility China is building at Djibouti on the Horn of Africa.

Other island targets of Chinese trade and investment such as Tonga, Fiji, Samoa and the Solomon Islands could serve as useful places for Chinese logistics and intelligence-gathering sites similar to those Beijing has built in the Spratly Islands in the South China Sea.

The price for going against Beijing's wishes is high. Palau used to be a favorite destination of Chinese tourists as well as investment. When Palau refused to sever diplomatic relations with Taiwan, the flow of Chinese money suddenly shut off, leaving Palau with empty hotels, unfinished construction sites and a mountain of debt to Chinese banks that shows no sign of shrinking.

A Chinese restaurant in Palau was empty on Aug. 4, 2018.   © Reuters

Chinese money has also been backing protests in the Commonwealth of the North Marianas Islands against U.S. efforts to use the islands for military training, including on Tinian. There, Chinese investors are planning a casino close to where U.S. Marines are being deployed from Okinawa. Recently, Chinese scientists have lowered acoustic sensors into the Mariana Trench near the U.S. territory of Guam, home to a major U.S. military base in the Western Pacific. These could be used to study the ocean or track submarines.

In the ancient Chinese game of Go, players attempt slow, move-by-move encirclement of their adversary. Individual moves are often ambiguous, shrouding intentions until counter-moves come too late. Fanciful? China has played Go in the South China Sea. Now it's playing the same game in the South Pacific.

Historically, democracies often prove vulnerable to just such slow accumulations of advantage. Fortunately, America has an advantage that China lacks; allies who share our concerns and will help share the burdens. At a time when some worry about the U.S. commitment to alliances, the South Pacific is where the Trump administration can join the leading efforts of Japan and Australia.

The leaders of Japan and Australia see the threat coming, and are taking steps to counter Beijing's moves. Australia has been the largest source of aid to the region, with $1.3 billion in grants slated for 2018-2019 alone. At the annual Pacific Islands Leaders Meeting (PALM) in 2015, Japan pledged a 55 billion yen ($460 million) assistance package. Meanwhile, U.S. aid to the region looks paltry by comparison.

Together the U.S., Australia and Japan have the tools through development aid, trade, capacity building and military cooperation to counter China's complex game in the South Pacific. Together they can make the world aware of Chinese ambitions and actions in the South Pacific, as in Asia as a whole. Douglas MacArthur stated it best -- the Pacific Ocean, including its vast chains of islands, constitute "a protective shield for all the Americas," but also for America's allies. We would all do well to pay heed.

Arthur Herman is a senior fellow and Lewis Libby is senior vice president at the Hudson Institute.