It depends on the circumstance. Some people are more sensitive to it than others.
For Example: Sometimes a nation decides to leave an alliance, or their previous alliance fails, and they advertise for recruitment. We had an incident one time where such an event happened, and within hours we sent a message to this nation with a proposal for joining us. Within those few hours they had already joined another alliance. They in turn talked (ran to and cried?) to their new alliance and this alliance (a rather large one) threatened us (a rather small alliance) with war for poaching.
My opinion was it was overreacting or a set-up. Either way, both that person and that alliance lost respect points from us.
I agree with the intentional poaching to bring economic or political harm is bad, yet both those that rush to war or bullying need to investigate before threatening.