With leaders like Hitler as her neighbor, France was left with slim options for avoiding WWII. It’s eminently so even other European leaders had seen it coming especially when Hitler rose to power in 1939. One of them being Winston Churchill of Britain who said this having prior knowledge of Hitler’s ideologies and his perception towards European neighbors:
“Thank God for the French Army”
(Source: The BBC)
France had the reputation for having one of the best armies and together with its allies, it seemed untouchable. Its leaders knew this and when the Germany was preparing for an attack, one of the commanders bragged it off as just a mere exercise.
First, France had to do something anyway as the situation in Germany continued to move from bad to worse. When WWI ended and the Treaty of Versailles signed, Germany was hardest hit. The world had laid blame on them and with it came several other punitive actions; hefty fines were imposed, restrictions on its military, loss of territory including colonies and many other measures.
All this weakened the economy of Germany and so its government. Definitely, the people felt the pinch and therefore they were angry and supported every action by its leaders which went against the world and which its leader Hitler shared. War was looming, France was better placed than the Germany as it had managed to rebuild its army after WWI, embarked on modernization and had some of the best military technology at the time. Again it had Britain as its ally and therefore if pushed to the wall by the Germans it could afford to hit back. And this happened in May 1940 when German troops started an offensive against her hence fighting back to protect her territory though several big mistakes by her leaders led to defeat.
Earlier on in 1938, France together with Britain had embarked on an effort to appease Germany, they had signed the Munich Pact which gave Germany the permission to invade Czechoslovakia but this appeasement never worked. They thought by appeasing the war-hungry Germany would change the mindset of Hitler towards making peace with his European neighbors and deter him from ever wanting to go to war with them- Something which never worked. So, when they saw the appeasement strategy fail, they knew the battle was on the way.
Another thing that led France to WWII was to honor the agreement they had entered together with Britain on Poland protection. They had pledged to protect Poland if it was under attack. In 1939 Germany forces crossed over to attack Poland which forced Britain and France give an ultimatum for Hitler to withdraw his troops but when Germany proved adamant, Britain and France had to honor the earlier signed pact and defend Poland.
So protecting its territories and those of its allies was top on the list for France to join WWII, but France was literally pushed to it against her wish. If asked, France would have chosen for dialogue whereas Germany would hear nothing less of a battle.