They see previous hints left around, like how fossils proved there were extinct animals on earth.
When using the justification that "the tactic was unavoidable," The negotiator is saying that the negotiator was not in full control of his or her actions and hence should not be held responsible.
If you are talking about plate tectonics, then it's 2-5 cm per year.
The power of the Government is limited in that Government cannot do everything it desires. This is so because it was elected by people, and assuming that the politicians in the goverment will want to be re-elected, they have to do what the people want, and not whatever they want: they have limits on their actions.
