Is the lack of an essential unifying framework to foreign policy surprising in a democracy like the US or Great Britain? To a first approximation Russian forei

Is the lack of an essential unifying framework to foreign policy surprising in a democracy like the US or Great Britain? To a first approximation Russian foreign policy on large issues like the Ukraine is whatever is in Vladimir Putin’s head. Similarly Chinese policy is driven by Xi Jinping. For those states the “unitary actor” theory is reasonable to the extent that Xi and Putin are themselves rational. In the US, U.K. and other multi party democracies a hypothetical “bipolar actor” theory is going to be a better approximation to the truth, given that control alternates between Democrats and Republicans, or Labor and the Conservatives. Surely this cannot be a novel insight to people in IR?