Unity in diversity means the oneness in the varieties.It is an expression of harmony and how different communities and people live together .
Example : India is the best country proving this concept for many years. India is a country where it is very clear to see unity in diversity because people of many religions, race, cultures and traditions live together.
I believe the answer is <span> the social exchange theory
</span><span> the social exchange theory is based on the assumption that all people are individualistic in nature.
</span>This theory believes that human only choose to interact with another human only if the benefit from interacting with that other human surpass the cost to interact with him. (which explains the reason some people choose to marry old -rich individuals despite negative perception that will be labeled to them)
Because he was assassinated by Serbian rebels. Most of Europe was allied with someone, a tangle of alliances. Serbia was allied Russia. Austria-Hungary didn't like Serbia. Well when the Archduke decided to visit Sarajevo, he was assassinated by a Serbian assassin. Because of that, Austria-Hungary wanted to punish Serbia and declared war. Well Austria-Hungary was allied with Germany and Italy. And Serbia was allied with Russia. Well Russia attacked Austria-Hungary and Russia was allied with both Great Britain and France.... So it triggered a chain reaction like that.
The battle of tippecanoe destroyed the hopes of a large indian confederacy,when the american soldier saw that the indian had british weapon,they knew the british were helping them resist the americans. this cause even more hatred towards the british than there had been before, this would ultimately serve as a catayst for the war of 1812, which would take place less than a year after.