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GPS measurements show that the New Hebrides arc is breaking apart as the d'Entrecasteaux ridge impinges against the arc and thrusts beneath it. The Australian plate and most of the arc are coming together at rates of about 100 - 120 mm/yr. However, the central New Hebrides (shaded segment) is converging with the Australian plate at only 42 mm/yr, or about half the minimum rate that it should (minimum rates from plate tectonic models indicated by dashed arrows). This and other evidence shows that a large segment of the arc is being pushed backward into the North Fiji Basin at rates of 38 to 85 mm/yr. This process profoundly affects local earthquakes and tectonics, but more importantly, it illustrates processes of island arc evolution and the power of GPS measurements to elucidate these processes.