Hey guys, sorry ahead of time for spewing out so many ideas lately, however...
I've got another. In most strategy games, you can create alliances in which other entities are obligated to come to your aid (or theirs) when war is declared on the coalition of allies. I was wondering if it would be possible, though, to introduce a diplomacy mechanic by which a third party (or multiple parties) will threaten to declare war on a kingdom if it does not cease war with another kingdom that favors a peaceful solution.
This scenario would classically be seen when an aggressor attacks another kingdom and is defeating them and the third party kingdoms mentioned prior want to see the expansion of the aggressor checked without necessarily having to go to war. The scenario might proceed as follows.
The large and militarily formidable Kingdom A has conquered many other smaller kingdoms, and sets its sites on Kingdom B. They declare war on Kingdom B, and swiftly capture 2 of Kingdom B's cities. These rapid and violent acquisitions greatly concern Kingdoms C and D. Kingdom B is certain that it cannot win the war, and is eagar for a peaceful solution. As a consequence, Kingdom B calls an audience with C and D, but while C and D are concerned about A's expansion, would prefer first to exhaust diplomatic options before going to war on B's behalf. Together, they confront Kingdom A and demand that peace be promptly made, lest C and D escalate the war on the side of B. Kingdom A determines that fighting all three will be a fruitless stalemate and decides to consolidate their modest gains by accepting the gunbarrel peace offer.