What is the ruling on giving a bribe to avoid illegitimate military service?

If the service is illicit, then there is no harm in giving a bribe to be rid of it. Bribery is that by which falsehood is established or truth is invalidated. As for what is given to establish truth or invalidate falsehood, it is not considered a bribe on the part of the giver, though it is a bribe on the part of the taker.