  This paper addresses the question of whether the International Linear
Collider has the capability of discovering new particles that have not already
been discovered at the CERN Large Hadron Collider. We summarize the various
paths to discovery offered by the ILC, and discuss them in the context of three
different scenarios: 1. LHC does not discover any new particles, 2. LHC
discovers some new low mass states and 3. LHC discovers new heavy particles. We
will show that in each case, ILC plays a critical role in discovery of new
phenomena and in pushing forward the frontiers of high-energy physics as well
as our understanding of the universe in a manner which is highly complementary
to that of LHC.
  For the busy reader, a two-page executive summary is provided at the
beginning of the document.
