China’s “Military Diplomacy” Between Thailand & Cambodia Is Becoming Trickier

Thailand appears to be intimating that it’s displeased with China’s arms sales to Cambodia, with the innuendo that China should curtail them out of respect for Thailand, which is now much more important of a partner for China than Cambodia is.

The Chinese Defense Ministry claimed that its arms trade with Thailand and Cambodia has nothing to do with the intense resumption of summer’s hostilities, which followed a report by Newsweek alleging that Thailand captured Chinese grenades and anti-tank unguided rockets from Cambodia. It’s no secret that China is Cambodia’s largest military supplier given their decades-long special relationship, but few also know that China has recently become Thailand’s largest one as well and now surpasses the US.

This fact was reaffirmed in the Stockholm International Peace Research Institute’s (SIPRI) “Trends in International Arms Transfers, 2024” report from March covering the years 2020-2024. SIPRI noted that Thailand was China’s third-largest arms export market during that period at 4.6% of its total sales while China was Thailand’s largest arms supplier at 43% of imports, far ahead of the second-place US at 14% despite Thailand being one of the US” “Major Non-NATO Allies”. This is part of a larger regional trend.

More trade between China and Thailand led to closer political and military ties, thus revolutionizing the regional strategic paradigm and creating the conditions for cooperating on a planned high-speed railway linking China’s Kunming to Singapore via Laos, Thailand, and Malaysia. All things considered, except for the reported possibility of Cambodia allowing China to exclusively use its newly renovated Ream Naval Base (which both have denied), Thailand is a much more important partner for China by all metrics.

Nevertheless, China still sells arms to Cambodia, most likely as part of its “military diplomacy” which parallels Russia’s own that it’s pioneered in other parts of the world. This concept refers in this context to arms sales to pairs of rival states in the hope of maintaining the balance of power between them so as to then mediate a political resolution to their disputes. It contrasts with the American policy of only arming one side in order to give them a military edge for coercing the other into unilateral concessions.

Russia is most known for practicing “military diplomacy” between Armenia and Azerbaijan, China and India, and China and Vietnam, with the first attempt having failed to result in a political resolution to their dispute while the last two have successfully maintained the balance of power between them. As regards China’s practice of this policy, it remained in the shadows till the New York Times published a report in September about “How Chinese Weapons Transformed a War Between Two Neighbors”.

While informative, the piece still tries to build the narrative that Chinese arms sales to Cambodia emboldened it to supposedly initiate hostilities. The jury is still out about who was responsible for summer’s clashes, with this analysis here arguing that it was Thailand and then the follow-up one here forecasting the extent to which it might go if hostilities didn’t end (or re-erupt again). Anyhow, the point is that China does indeed practice “military diplomacy” with both, but it’s now becoming trickier.

Thailand appears to be intimating that it’s displeased with China’s arms sales to Cambodia, with the innuendo that China should curtail them out of respect for Thailand, which is now much more important of a partner for China than Cambodia is. The subtext is that China’s role as a mediator would be damaged if Thailand concludes that it’s resupplied Cambodia since summer’s hostilities. That could in turn disrupt their high-speed rail plans if it happens and thus China’s entire regional connectivity vision.