Why is Guam critical to the US?

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This is the script for my video posted on August 24, 2026. Watch it on TikTok.

You might think that Hawaii is as far west as the US goes, but you'd be wrong. Guam is over 6000km west of Hawaii and nearly 10000km from California, making it the most distant populated US soil. So how did the US gain control of Guam to begin with, and how does it change the US’s geopolitical dynamics?

Guam was first settled by the CHamoru people millennia ago. Ferdinand Magellan was the first European to make landfall in the Mariana Islands and Guam in 1521, though formal Spanish colonization didn’t begin until 1668, after which the CHamoru continuously fought them for decades.

By 1710, the number of CHamorus declined from about 40000 to just 4000, likely due to a combination of disease and conflict.

The Spanish retained control for nearly two centuries. But in 1898, the USS Maine exploded and sank in Havana harbor. The American press blamed Spain, and the Spanish-American War began, though of course a later Navy investigation pointed to an internal coal fire as the source of the Maine’s sinking.

Months in, the USS Charleston was escorting troop transports to Manila when it entered Guam’s waters and fired shells at the unmanned Fort Santa Cruz. The Spanish garrison had no knowledge that war had been declared and mistook the bombardment for a ceremonial salute. Officials rowed out to apologize for being unable to return the salute because they lacked gunpowder, and Guam’s Spanish governor immediately surrendered with no casualties.

The 1898 Treaty of Paris saw the end of the Spanish Empire in most ways. Spain handed over the Philippines for $20m and ceded Puerto Rico and Guam to the US.

Naval governors ruled Guam largely by decree for decades, and CHamorus petitioned repeatedly for US citizenship and civil government to no avail.

Japan began bombing Guam the same morning as Pearl Harbor when you account for the date line, then landed troops two days later. Roughly 5900 Japanese forces faced a US garrison of about 270 sailors, 150 Marines, and around 250 locals. The naval governor surrendered, and the next 2.5 years saw Japan use forced labor to build airstrips, replace English with Japanese, and commit horrifying acts of violence against the locals.

When US forces finally approached again in July 1944, the Japanese forced the CHamoru population into internment camps in the jungle. Hundreds died from disease, starvation, and execution. But US forces suffered nearly 8000 casualties in the Battle of Guam, and roughly 18k Japanese were killed. Guam observes Liberation Day every July 21st.

In the aftermath of the war, Harry Truman signed the 1950 Organic Act of Guam, which granted locals US citizenship, established a civilian government, transferred administration from the Navy to the Department of the Interior, and defined Guam as an unincorporated organized territory, meaning the full constitution does not automatically apply. Unfortunately this did not give people a vote for president or voting representation in Congress.

Despite this progress, the US military condemned large amounts of CHamoru land after the war, often with inadequate or no compensation. CHamorus still have active land disputes today.

The thing is, Guam only has about 200 square miles of land to begin with, but it’s extremely important to the US under the island chain concept, a Cold War era map of the Western Pacific that Chinese planners now use as heavily as the US.

The idea is that two island chains serve as defensive perimeters across the region, with the first running from the Kurils down through Japan, the Ryukyus, Taiwan, and the Philippines to Borneo. The second island chain is a fallback position further east, and Guam is its stronghold.

Consequently, even after the military stopped administering the territory, it retained about 25-30% of the island’s land for military purposes.

There are two bases anchoring the military’s presence. Andersen AFB, located in the northern part of the island, hosts rotating bomber deployments, one of the Air Force's largest aviation fuel storage facilities, and a major munitions depot. The US ended its continuous bomber presence there in 2020 in favor of shorter, less predictable rotations.

Naval Base Guam hosts attack submarines and a submarine tender for maintenance, repair, rearmament, and logistical support. The harbor there is one of the largest deepwater harbors in the region.

Guam also hosts missile defenses, anchored by a Terminal High Altitude Area Defense battery, or THAAD, that's been there since 2013. The US is now building something far larger around a ground-based version of the Navy's Aegis system, with Patriots for point defense. Layering these together would make it far more likely that Guam could intercept, say, an incoming North Korean ballistic missile. But as of March 2025, there are six launchers and one radar on the island. The first new elements arrive in 2027 and the full architecture won’t be finished until 2032.

In 2017, North Korea announced detailed plan to fire four Hwasong-12 intermediate range ballistic missiles, or IRBMs, over Japan and strike about 30-40km off Guam’s shore. Kim Jong-un reviewed the plan, said he’d wait and see what the US did, and never gave the launch order. But it demonstrated to everyone just how dire the risk is.

China also operates several weapons systems explicitly designed to target Guam. The DF-26 “Guam Killer” is an IRBM with the ability to carry a nuclear warhead, but there is no way to tell if an incoming DF-26 is conventional or nuclear, making it all the more important for missile defenses to work.

About 7000 uniformed personnel are stationed on the island today, down from around 26000 during the Cold War. Troops and dependents comprise around 14% of the island’s total population, and that number will likely rise as the US Marine Corps moves forces from Okinawa. Interestingly, Japan is providing about 3b dollars to help finance the relocation. Japanese and Australian forces also rotate through for exercises, though none are permanently based there.

In 2000, Guam passed a law allowing a plebiscite to take place among the native inhabitants of Guam that would select from three status options: statehood, free association, or independence. But the CHamoru only comprise about 37% of the island’s population today, and in 2019, the US Ninth Circuit Court held that the “native inhabitants” restriction was a proxy for race and violated the 15th Amendment. The plebiscite can’t legally go forward as proposed, and Guam hasn’t figured out how to proceed, even as Palau, the Marshall Islands, and Micronesia became sovereign states under compacts of free association, and the neighboring Northern Marianas became a US commonwealth.

Defense spending equaled about 41% of the island's GDP in 2022 though, the highest share of any state or territory, so there's pressure not to disrupt it. Guam also has the highest per-capita enlistment rate in the country, and for a lot of young people, service is the clearest path off the island. And on the US government side, there are logistical advantages to holding onto Guam like the fact that there are no host-nation constraints on access or politics around basing like the US has had in Okinawa.

Not to mention, much of Guam’s construction workforce relies on foreign labor, mostly from the Philippines, on H-2B visas, but in late 2015 the federal government removed Guam’s exemption from the national H-2B cap and denials became near total. By 2018 only 71 H-2B workers were left on the island, and for one month that year there were zero. It took years of pressure from Guam's government and its delegate, plus the military's own need for labor, before a workaround was made.

Guam is already fragile without all of this artificial disruption. The port is a serious logistical chokepoint for military materiel and civilian supplies alike. The power grid is fragile and vulnerable to typhoons. 80% of the island’s drinking water comes from a single aquifer, and even when contaminants are detected, wells can’t be shut down because there’s no alternative. This is a serious issue when military bases openly burn and detonate munitions and fuel spills into harbors and groundwater.

From a strategic standpoint, Guam is a very vulnerable single point of failure. It may be convenient in some ways, but it’s not especially survivable under threat of missile attacks, and it’s incredibly far from the rest of the US’s military infrastructure. At the same time, the island’s economy and identity rely on the military, making them difficult to separate.

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