Guam’s Strategic Importance in the Indo-Pacific

As the westernmost U.S. territory in the Indo-Pacific, the small island of Guam has been a valuable strategic asset for decades, and today it hosts a growing American military presence. Guam’s location—closer to Beijing than to Hawaii—makes it ideal for U.S. power projection amid rising tensions in the South China Sea, Taiwan Strait, and Korean Peninsula. At the same time, this military presence has sparked debate over the outsize role of Washington’s influence on Guam’s economy, government, and environment.

Why does Guam matter?

Guam is commonly referred to as “the tip of the spear” of the United States’ ability to project its military might across the Indo-Pacific. Experts say the island’s proximity to countries including China, Japan, the Philippines, and North Korea makes it a linchpin of U.S. power in an increasingly tumultuous region.

Guam has repeatedly been a centerpiece for U.S. regional military strategy in times of conflict. During World War II, the island was a forward base for U.S. operations in the Pacific. During the Vietnam War, it hosted bombers headed for missions in Southeast Asia, in addition to serving as a transit point for Vietnamese refugees en route to the United States.

In recent years, Guam has become even more important as U.S.-China tensions mount and Washington grows more concerned about Beijing’s aggression in the South China Sea and a potential Chinese attack on Taiwan. The U.S. Defense Department’s 2022 National Defense Strategy highlights Guam’s centrality to U.S. strategic deterrence in the Indo-Pacific. The island hosts a U.S. Air Force base, naval base, long-range bombers, and nuclear-armed submarines.

What is Guam’s status?

Guam is under U.S. jurisdiction as one of five permanently inhabited, unincorporated territories of the United States. After more than two centuries of Spanish rule, Spain ceded the island to the United States at the end of the Spanish-American War in 1898, at which point it was placed under control of the U.S. Navy. Washington established a naval base on Guam the year after. 

In the decades that followed, Guam’s geopolitical importance grew. The island was heavily contested between U.S. and Japanese forces during World War II before the United States recaptured it in 1944. It wasn’t until U.S. President Harry Truman signed the Guam Organic Act of 1950—transferring federal jurisdiction from the Navy to the Department of the Interior—that Washington established a civilian government on the island and gave U.S. citizenship to Guamanians. 

Because it is a U.S. territory, the island’s residents use the U.S. dollar, pay most federal taxes, and receive federal funding, similar to other territories such as Puerto Rico. However, as it is not a U.S. state, Guamanians are ineligible to vote, including for president; they instead have elected governorship and are represented in the U.S. House of Representatives by a non-voting delegate. The island’s occasional pushes for independence have not succeeded. 

What is the U.S. military’s role on Guam?

The U.S. military maintains a heavy footprint in Guam. The Defense Department owns some 25 percent [PDF] of Guam’s land. In the early 2000s, there were approximately 2,500 U.S. troops stationed on the island, down from a Cold War-era high of 26,000; today that number is again on the rise, and now totals some 9,700 uniformed personnel. These troops and their dependents comprise about 14 percent of the island’s population. 

Further, the Defense Department’s total spending [PDF] in Guam for fiscal year 2022 was $2.5 billion, approximately 41 percent of the island’s gross domestic product (GDP). Military construction projects account for many skilled labor jobs on the island, which are typically granted to foreign workers, predominantly from the Philippines, and to a lesser extent, from Thailand, Turkey, and South Korea to supplement worker shortages. In 2024, the number of foreign workers passed a record high of 5,500 people due to several major new military projects, including improved missile defense systems.

Despite this federal funding, roughly 17 percent of households live below the poverty line. Meanwhile, military base expansions have been detrimental to Guam’s ecology and endangered species. Recent reporting by environmental groups revealed that the military disposes of hazardous waste, such as leftover munitions, through burning or detonation. Conservation groups and Indigenous CHamoru activists are currently suing the military in federal court for failing to comply with national environmental policies.

Why is the United States investing more in Guam?

In 2023, the Department of Defense issued a five-year, $7.3 billion military construction plan for Guam, including an additional $1.7 billion for an integrated missile defense system. The department has also pushed for more funding to be allocated to the island under the Pacific Deterrence Initiative and other federal funding streams.

One reason for the buildup is a plan to relocate some four thousand Marines from the Japanese island of Okinawa to a new Marine Corps base on Guam starting in December. The move follows the United States’s agreement with Japan to reduce the U.S. military presence in Okinawa. 

Experts say the island could serve as a critical logistics hub in a potential conflict over Taiwan. But Guam’s strategic value—its proximity to China and North Korea—also makes it more vulnerable to attacks, and some experts argue that the island is not prepared to defend its military installations or evacuate American civilians from surrounding countries should war break out. 

In 2017, North Korea threatened to strike U.S. military targets in Guam, and in 2019, China unveiled a ballistic missile colloquially known as the “Guam killer.” China also recognizes Guam’s centrality to U.S. influence in the region; in May 2023, Beijing reportedly launched a cyber malware attack on Guam’s critical infrastructure, maritime operations, and transportation. Many believe that this operation was intended to probe for weaknesses that could be exploited to deny the United States the ability to operate from the island during a conflict.

Other U.S. funding seeks to address Guam’s environmental challenges. Guam’s location puts it at risk of extreme weather events, such as typhoons and rising sea levels in the Pacific. President Joe Biden’s Inflation Reduction Act aimed to address some of the ongoing costs of the climate crisis in Guam, including by funding coastal conservation efforts and providing jobs in clean energy.  

Michael Bricknell and Will Merrow created the maps for this In Brief.