Martin van Creveld, in Forward, draws a parallel between ancient and modern at the conclusion of an article on the Iraq war [thanks to Hume's Ghost at Crooked Timber]:
For misleading the American people, and launching the most foolish war
since Emperor Augustus in 9 B.C sent his legions into Germany and lost
them, Bush deserves to be impeached and, once he has been removed from
office, put on trial along with the rest of the president's men. If
convicted, they'll have plenty of time to mull over their sins.
Not so, says another commentator at Crooked Timber:
Van Creveld needs to read up on history. Those legions were not lost
after being “sent in”, they were the garrison engaged in the normal
Roman pacification process after the inital conquest had
already been accomplished (Varus, their commander, was the newly
appointed governor of Germania). The rebellion led by Arminius was both
energized by Varus’s heavy-handed tactics as governor, and enabled by
his failure to respond to quite specific warnings about the plot.
Unlike Iraq, this may actually be a case where a very obtainable
objective was sabotaged by incompetence. So it’s pretty a dicey example
to use in the current case.
For more on "Give me back my legions" Varus, see (e.g.) Livius.org.