Make sure you respond to any pending war requests before the expire time.
If you fail to to respond before the expire time, the war will automatically start.
To decline a war, you will have to pay a fee of $40,000,000 + $1,000,000 + $80,000,000 * 1.
The total costs to decline this war: $121,000,000 (Prices go up significantly the more wars you decline.)
If state indicates Preparing the expire time indicates the time of when the war will start.
If state indicates WARTIME the expire time indicates the time of when the war will end.