What policy did kennedy lay the groundwork for at the end of his presidency?
isolationism
détente
flexible response
brinkmanship

I think the answer is detente. This is because he was able to ease various political situations in the US by negotiating with the people involved in the situations. He was able to ease economic recession throught Keynesian practices. He was also able to help diffuse the issue during the Cuban Missile Crisis by negotiating with the Soviet Union

Countries of eastern europe.