Here are some historical examples.
Pope Urban II. at 27. November 1095 wants to "free" the holy land. He told that priests get killed there and holy virgins raped.
Those raping is a classic and is still in use by propaganda in ww2.
Gustav Adolf the sweden king officialy invades germany to help the Lutherians but he had other reasons.
The Italian-Ottoman war was started with the stated bad treatment of Italians in Tripolis. The following ultimatum to give Tripolis to Italy in the next 48 hours started the war 1911 against the Ottoman Empire.
Hitler who actually sayed to get Danzig back anyway initiates an attack on a radio station Gleiwitz to "shoot back" and invade poland.
There are many more. Nearly every war had his reason and if there was none it had to be invented to make it look better. The best way to start a war is to provocate and let the enemy declare it.
If you know more please post them (only the invented ones).
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"Werden wir richtig informiert?" Do we get the right information?
Karl Jaspers