Why did the German invasion of Danzig provoke war?

the british and french stated that if Germany invaded Poland, they would declare war on Germany

answer; (a) he was a u.s senator for 38 years;

congress also has implied powers, which derive from the necessary and proper clause of the constitution and permit congress "to make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this constitution in the government of the united states.