  After a brief review of the Big Issues in particle physics, we discuss the
contributions to resolving that could be made by various planned and proposed
future colliders. These include future runs of LEP and the Fermilab Tevatron
collider, B factories, RHIC, the LHC, a linear electron-positron collider, an
electron-proton collider in the LEP/LHC tunnel, a muon collider and a future
larger hadron collider (FLHC). The Higgs boson and supersymmetry are used as
benchmarks for assessing their capabilities. The LHC has great capacities for
precision measurements as well as exploration, but also shortcomings where the
complementary strengths of a linear electron-positron collider would be
invaluable. It is not too soon to study seriously possible subsequent
colliders.
