  We study the equations of Wheeler-Feynman electrodynamics which is an
action-at-a-distance theory about world-lines of charges that interact through
their corresponding advanced and retarded Li\'enard-Wiechert field terms. The
equations are non-linear, neutral, and involve time-like advanced as well as
retarded arguments of unbounded delay. Using a reformulation in terms of
Maxwell-Lorentz electrodynamics without self-interaction, which we have
introduced in a preceding work, we are able to establish the existence of
conditional solutions. These are solutions that solve the Wheeler-Feynman
equations on any finite time interval with prescribed continuations outside of
this interval. As a byproduct we also prove existence and uniqueness of
solutions to the Synge equations on the time half-line for a given history of
charge trajectories.
