Republicans want to give part of Ukraine to the Russians. This is very similar to 1938 when Chamberlain got an international agreement
that Hitler should have the Sudetenland of Czechoslovakia in exchange for Germany making no further demands for land in Europe.
Chamberlain said it was 'Peace for our time'. Hitler said he had 'No more territorial demands to make in Europe.
Six months later, in March 1939, German troops took over the rest of Czechoslovakia. Poland seemed to be the next most likely victim of Nazi aggression and Chamberlain made an agreement with the Poles to defend them in Germany invaded. Hitler did not think Britain would go to war over Poland, having failed to do so over Czechoslovakia. He sent his soldiers into Poland in September 1939. Two days later, Britain declared war on Germany.