  We explore some aspects of causal time-delay in open string scattering
studied recently by Seiberg, Susskind and Toumbas. By examining high-energy
scattering amplitudes at higher order in perturbation theory, we argue that
causal time-delay at G-th order is 1/(G+1) times smaller than the time-delay at
tree level. We propose a space-time interpretation of the result by utilizing
the picture of the high-energy open string scattering put forward by Gross and
Manes. We argue that the phenomenon of reduced time-delay is attributed to the
universal feature of the space-time string trajectory in high-energy scattering
that string shape at higher order remains the same as that at tree level but
overall scale is reduced. We also discuss implications to the space-time
uncertainty principle and make brief comments on causal time-delay behavior in
space/time noncommutative field theory.
