Kuala Lampur, June 19 -- When Russia annexed Crimea in 2014, it was swiftly ejected from the G8, reverting the influential economic forum back to the G7. That decision was made on the premise that great powers must abide by international law. But nearly a decade later, the grouping faces yet another foundational rupture - not by expelling a member, but through the voluntary abandonment of the G7's raison d'etre by the United States under Donald Trump.

The original G7-formed in the wake of the 1973 oil crisis and the subsequent economic instability wrought by the Yom Kippur (or Ramadan) War between Egypt and Israel-was intended to stabilize the Western-led economic order. It emerged at a time when US global dominance was waning, following...