Kipling was addressing the Americans, who were colonizing the Philippines
The answer is the last choice, commonality.
Saul, an Israeli king, ruled over Israel during the 11th century BC. David took the throne right after Saul did. David was important to the Jews and Christians because he was a great king who ruled over his people and did what God told him. David was also important to Christians as he is one of Jesus' direct ancestors.
I believe the answer is: It delayed or extended nationalist struggles.
The nationalist struggles come after different nations started to fully embodied nationalist movement, which make them tend to incline to prove their nation's superiority over another nations. This type of thinking often lead to conflicts among these european nations.
