 Quantum entanglement results in a form of nonlocality that is alien to classical physics. Even if we assume that the reduced states of \(A\) and \(B\) do not completely characterize their physical states, but must be supplemented by some further variables, there are quantum correlations that cannot be reduced to correlations between states of \(A\) and \(B\); see the entries on  Bell’s Theorem  and  action at a distance in quantum mechanics.