Their economy is linked, because many English are based in America.
Economic system linked
They have the same language or a very near language with few variation
Same language
Military alliance
They are linked Military, because their Membership NATO (North Atlantic Treaty Organization)
Linked History
Their history is linked, The England colonised America, which is the start of the USA, we know. They were allied during the WW1 and the WW2.
Special relationship
