I would say France and Poland.
Explanation:
After many times of N. Chamberlain and E. Daladier governments concessions', especially in Munich in September 1938, Britain and France were sure A. Hitler do not have other territorial claims. Even A. Hitler said in Bad Godesberg about that.
The British and French people were sure that there would be no war because A. Hitler have got Sudeten Region he wanted.
When A. Hitler initiated a Poland campaign (1939), France, as British Empire, had no choice, but declare the war. Partially, because they had a military alliance with Poland; partially, because France already had the same type of agreement with Czechoslovakia and just broke the treaty, so not declaring the war in this case would be very stupid.
But I can't say French economic were ready for another World War, as I can't say French leaders were ready. Declaring the war in this case was rather a necessary thing, than their desire.
Nobody can say for sure, what would happen if Germany declared war against USSR
, instead of signing the Molotov-Ribbentrop Pact and declared war against Poland. Many Soviet historians and even some British (for example, Leibovitz) says that the British Empire and France considered the USSR a greater threat than Germany
.
The main thing about France: it was rather a necessary thing, than a desire, though the desire there was too, indeed.
About Poland that's much simpler. Poland was ready, no doubt. Of course they had no chances against the German Army but it's quite different situation than with the France, for example.
Why also Poland had more desire is because Germany attacked Poland. A. Hitler didn't declare war against France or Britain, but against Poland, there is another important point.
So, there could be a following formula: France had more power and less desire, Poland had less power but more desire.
