the Franco–Siamese Treaty of 1907

Mainland Southeast Asia’s strategic equilibrium ultimately rests on the mutually reinforcing foreign policy approaches of Hanoi and Bangkok. Vietnam’s “ Four Nos ” doctrine – which commits it to no military alliances, no siding with one country against another, no foreign military bases on Vietnamese soil, and no use of force or threat of use of force in international relations – is often interpreted as the backbone of the country’s policy of non-alignment in the current phase of intensifying great power competition. However, the recent Cambodia-Thailand border conflict reveals a no less important aspect of the policy, which is that Hanoi also seeks to be non-aligned with regard to disputes among its peer neighbors, except for Vietnam’s sole treaty ally Laos. This is a huge policy reversal compared to the heyday of the Third Indochina War (1977-1991), when Hanoi backed the People’s Republic of Kampuchea in its border clash with Thailand, partially resulting in Vietnam being internatio...