Defensive pacts

[razor436]

If defensive pacts are anything like the ones in Civ 4, I'll scream.

Civilization 4
If you and a friend are in a defensive pact, and an enemy declares war on you, then your friend declares war on them and the defensive pact is canceled. Next turn another enemy declares war on you and there is no longer a defensive pact in effect to help you out.​

 

[Col Mustard]

Defensive Pact
Once you have acquired the Chivalry tech, you may engage in a Defensive Pact. Defensive
Pacts are always mutual. If a signatory to a Defensive Pact is attacked, the other partner is
automatically at war with the attacker.
A Defensive pact lasts for 30 turns. When that time has elapsed, the pact lapses unless it is
renegotiated. The defensive pact is nullified if one of the participants declares war on anybody.

Straight from the manual, so I dont think you have to worry. One thing that I've always wanted was a combine forces pact where you and your ally shared where your attacking troops are and what you wanted to do with them. This would lead to a more effective pacts and warfare.