Customer is etymologically related to Custom. Customer is related to Buyer. 
War is related to Human. People can be Human. People is related to Head. Head is related to Place. 
Custom <--EtymologicallyRelatedTo-- Customer <--RelatedTo--> Buyer 
War <--RelatedTo--> Human <--HasProperty-- People <--RelatedTo--> Head <--RelatedTo--> Place 