Geopolitics › Alliances & institutions
US alliance network ('hub and spokes')
Treaties 1951–54· Alliance or organization
FactTreaties, membership, measured data, events.
The web of US defense treaties, especially in Asia, where Washington built separate one-on-one alliances instead of one NATO-style bloc.
See it on the Geopolitics map →The picture
After World War II the US signed mostly bilateral treaties in quick succession: with the Philippines, Australia and New Zealand (ANZUS) and Japan in 1951, South Korea in 1953 and Taiwan in 1954 (ended 1980). Thailand is also a treaty ally. The US is the hub; allies are spokes, tied to Washington more than to each other. Over 80,000 US troops are based in Japan and South Korea alone. Allies now also link with each other, through the Quad, AUKUS and Camp David.
Why it matters
These treaties let the US keep forces near China, Russia and North Korea and give allies a nuclear umbrella; Trump's demands that allies pay more test that bargain.
Think of it like
Like a master landlord with separate leases for each tenant: every tenant deals with the landlord, rarely with each other.
Key facts and numbers
Published treaty texts (1951–54), Pentagon troop counts, and histories of the 'San Francisco System' built around the 1951 Japan peace treaty; 'hub and spokes' is a common scholars' label.
What to watch
Outlook: whether the spokes become a 'latticework' of ally-to-ally ties, and whether that hedges against, or substitutes for, a less reliable US hub.
Inside this (6)
Connections (2)
▸United States is the hub of US alliance network ('hub and spokes')Fact
The relationship
The US signed every treaty and supplies the forces, nuclear umbrella and intelligence; allies supply bases, host-nation funding and regional access. Each ally's main tie runs to Washington, so the network depends on US commitment. Under Trump, the US asks allies to spend and pay more, and to back its aims on China.
Since when and why
Treaties signed in San Francisco, Washington and Manila, 1951–54; US Indo-Pacific Command in Hawaii now oversees forces across the region.
How we know
Published treaty texts, Pentagon troop and base data, host-nation cost-sharing agreements, and joint statements from US–ally summits.
What to watch
Outlook: whether allies grow more self-reliant, or even seek their own nuclear weapons, if they doubt US guarantees; polls in South Korea show strong support for that.
▸Philippines is a treaty ally in US alliance network ('hub and spokes')Fact
The relationship
The 1951 Mutual Defense Treaty commits each side to act against an armed attack on the other. Washington says it covers Philippine forces, coast guard ships and aircraft anywhere in the South China Sea. Marcos expanded US access to nine bases, including northern sites facing Taiwan, and hosts US missile systems.
Since when and why
Treaty signed in Washington, August 30, 1951; base-access deal (EDCA) 2014, expanded 2023; yearly Balikatan exercises.
How we know
The treaty text, repeated US statements under Biden and Trump, and US deployments of Typhon and NMESIS missile launchers to the Philippines.
What to watch
Whether the US would fight over a shoal or a coast guard clash, and whether China presses harder if US attention shifts elsewhere.