I propose that players should have to pay a war refund if they defect during the first 48 hours of war. Refund 10gc per current networth point of the defecting empire regardless of the original cost of declaring. After 28 hours, decrease the cost of defecting by 0.5gc/point/hour. If multiple wars are active then count the time since the first war was declared.
The defecting player would pay the cost in the same way that loans are paid off.
Similarly, if the leader or first officer kick empires out of an alliance the treasury would have to pay the cost.
The current version 4a rules make it extremely risky and expensive to declare war on larger alliances. The alternative, declaring many wars on small (equal size, +/-2X) alliances, is not much fun for anyone involved. With a partial refund it would be less lame when the enemy disperses. At least you could try again after 32 hours.
The home page says that imperiaonline is a "
Medieval Real-Time War Simulation!".