Dry Tortugas, Florida–I was visiting the Dry Tortugas, a collection of islands, sand bars and reefs 70 miles west of Key West, and, curiously, the first thing that came to mind was the South China Sea and disputes over similarly tiny specs.

Fort Jefferson, Dry Tortugas: a model for China.

A giant brick bastion sits squat on the main island of the archipelago and is called Fort Jefferson. Way back in 1845, it’s construction exemplified the determination of the still-young United States to protect is coastal ports. The fort and its harbor was meant to serve as a way station for warships patrolling the Gulf of Mexico and defend the harbors of New Orleans, Mobile and Pensacola.

Six-sided Fort Jefferson was never completed, and during the US Civil War it was a prison for Union deserters. Its most famous inmate was Dr. Samuel Mudd, who was convicted for conspiracy in the assassination of Abraham Lincoln by John Wilkes Booth. Booth, after shooting Abraham Lincoln jumped the Ford Theater balcony and broke  his leg; Mudd splinted it and served four mosquito-filled years at Fort Jefferson. The Dry Tortugas other claim to notoriety was its service as jumping-off point for the USS Maine, a naval that, when it harbored in Havana Harbor, got blown up. The incident set off the Spanish American War.

The Dry Tortugas are now a national park.

No one ever actually challenged the US control of the Dry Tortugas or invade the US through the Gulf of Mexico and by the 20th Century, American strategic depth ballooned: the naval base at Guantanamo Bay, Cuba, and tutelage over Cuba, the building and ownership of the Panama Canal, takeovers of Puerto Rico and the (US) Virgin Islands cemented US dominance of the Caribben Sea. Meanwhile, in the Pacific Ocean, possession of the Philippines, Hawaii, Guam and American Samoa, along with a bunch of other atolls and reefs brought US naval power forward to the shores of Asia.

What does this have to do with the South China Sea? Like 19th Century America, Beijing aspires to control shipping lanes fronting its ports and warn everybody else away. The Americans were mainly concerned about Spain. The Chinese want to push the Americans out and is starting by laying claim to everything within a self-declared U-shaped “six dash line” zone that puts almost the entire South China Sea in their hands.

China’s own Dry Tortugas: one of the Spratly islands.

The Peoples Republic faces an array of close-by American projections of power never dreamed of at the time Fort Jefferson was constructed or even even into the 20th Century. Among them are US military bases in Japan and South Korea along with the American alliance with the Philippines. Expanding China’s reach into the South China Sea and northward into the East China Sea off Japan as well, where it claims some islands, permits it to dominate its  neighbors and effectively make it harder for the US to defend Taiwan, which China claims as its own, as well as possibly Japan.

In effect, China is not only following in the footsteps of the United States but other once-prominent seagoing nations, including the Spain, Portugal, Holland and Great Britain, that created ports and colonies along vast shipping routes. Besides constructing air strips and harbors on reefs and outcroppings in the South China Sea, Beijing is building ports  in Myanmar and in Pakistan at the mouth of the Persian Gulf and setting up a military base in Djibouti. These days, this kind of activity is known as providing “strategic depth” and “power projection.”

Of course, neighboring states are contesting the China Sea activities. The Philippines recently won an international arbitration case that rejected China’s claim to much of the South China Sea. Vietnam, with its own history of hostilities with China, objects to Beijing’s claim to the Spratly and Paracels islands and made a deal with old foe, the US, to purchase American arms.

None of this is going to stop China. Beijing has its own version of Manifest Destiny, an expansion of maritime reach designed to end centuries of being hemmed in by potential enemies from the sea and land. And for the first time since the end of World War II, the US reach is being pushed eastward in the Pacific.

American Enterprise Institute’s alarmist take.

Rand Corp. on China’s military expansion plans.

Where the US and China disagree.