The long-term nonlinear dynamics of a Keplerian binary system under th
e combined influences of gravitational radiation damping and external
tidal perturbations is analysed. Gravitational radiation reaction lead
s the binary system towards eventual collapse, while the external peri
odic perturbations could lead to the ionization of the system via Arno
ld diffusion. When these two opposing tendencies nearly balance each o
ther, interesting chaotic behaviour occurs which is briefly studied in
this paper. It is possible to show that periodic orbits can exist in
this system for sufficiently small damping. Moreover, we employ the me
thod of averaging to investigate the phenomenon of capture into resona
nce.