The Circum-Antarctic Ocean plays a particularly important role in the present-day global ocean circulation system, connecting the three major ocean basins, and acting as the intermediary of global water-mass exchange. As the global "blender" of water masses, changes in its tracer inventory through time reflect the vigor of the global thermohaline circulation (THC) system. Nd isotopes provide a unique potential to quantify present and past ocean circulation changes, as the only quasi-conservative paleocirculation tracer. We present the first Nd isotope record representing the Circum-Antarctic over the last 28 kyr. First order observations include shutdown of the THC during Heinrich Event 1 and during the early part of MIS 2, and a distinct but less intense weakening during the Younger Dryas, but increased THC vigor during the Last Glacial Maximum. Ongoing work with greater temporal resolution and on complementary records will allow quantification of THC intensity through time.