Why US defence strategy may push South Korea, Japan towards ‘radical’ security realignment

Washington’s latest defence strategy of providing “more limited US support” to its allies is expected to damage domestic backing for leaders in Japan and South Korea and spur greater momentum among regional countries towards military self-reliance.Analysts also warn that such a realignment could lead to a “radical swing” in regional security calculations, and in the case of South Korea, weaken its deterrence against the North.In the National Defence Strategy (NDS) released by the US Defence Department last Friday, Washington called on allies and partners to take “primary responsibility” for defending themselves.The Pentagon also made clear that Washington would offer limited support in line with the shift in US President Donald Trump’s security focus away from the Indo-Pacific region.“Ours is not a strategy of isolation,” the document states, adding that through the America-first lens, Washington’s “alliances and partners have an essential role to play”.Reiterating Trump’s long-standing view that the US alliance system was “one-sided” in favour of allies, the NDS echoes the National Security Strategy released last month, which urges America’s partners to raise their defence expenditure.Pointing to a “new global standard for defence spending” of 5 per cent of gross domestic product, the NDS states that this should apply to allies and partners around the world, “not just in Europe”.