Was it the United State's war at that point?
NO! It was a European Regional conflict.
I did not say that the US was obligated, I only took issue with the idea that it was wrong for the British to "sit" during the 8 months from sept 39 - May 40, they were not capable of attacking the Germans without the co-operation of the French, who declined to push too far into Germany
Whole lot of good that did them!
The period WAS put to good use, as the British fighters in 1940 were Hurricanes, in 1939 they still had bi-planes! The winter was also put to good use, at least by the BEF, training preparing defences. (that were later abandoned by the forward swing into Belgium - see "inept planning" below) The BEF and to some extent the French were capable of defending against the Germans in 1940 it was the inept planning leadership of the French high command that allowed the stunning german victory.
If the French and British governments had not followed a policy of appeasement, none of it would have ever happened anyhow.
There was some feeling that the Germans were too harshly punished after WWI. It was also felt by some that if they redressed some German complaints, a major war could be avoided. They did not expect that Hitler would turn out to be a mad warped dictator (obviously they had not read his book!) I'm not going to defend appeasment here, I didn't agree with it, although it was a very complicated question, not black white as some make it out to be.
Because they guaranteed the independence of Poland prior to the invasion. They chose to give an ultimatum to Germany to withdraw from Poland.
And Poland was eventually liberated from the Germans. They had hoped that an ultimatum would force Hitler to back down, turned out it didn't work
Did the United States do this? No because it was at that point a regional European conflict and remained so until Japan attacked Pearl Harbor and Germany declared war on the United States.
Ever heard of the Franco-Polish Military Alliance
France guaranteed she would grant Poland military credit in case of a war between Poland and Germany. It also stated that it would start minor air and land offensive immediatly
and to start a major offensive with 15 days after the declaration of war.
France declared war on Germany on Sept 3, 1939.
I'm not going to answer for the French here, someone else can take up the torch.
Now for the ]United Kingdom.
On March 30, 1939, the government of the United Kingdom pledged to defend Poland, in the event of a German attack, and Romania in case of other threats. The British "guarantee" of Poland was only of Polish independence, and pointly excluded Polish territorial integrity.
"This declaration was further amended in April, when Poland's minister of foreign affairs Colonel Józef Beck met with Neville Chamberlain and Lord Halifax. In the aftermath of the talks, a mutual assistance treaty was signed. On August 25 the Polish-British Common Defence Pact was signed as an annex to Polish-French alliance. Like the "guarantee" of March 30, the Anglo-Polish alliance committed Britain only to the defence of Polish independence. It was clearly aimed against German aggression. In case of war, United Kingdom was to start hostilities as soon as possible; initially helping Poland with air raids against the German war industry, and joining the struggle on land as soon as the British Expeditionary Corps arrived in France. In addition, a military credit was granted and armament was to reach Polish or Romanian ports in early autumn.
OK, I will have to state that puting a treaty on paper with the Poles was a bad idea considering the British position. They still could have given Hitler an ultimatum without tying themselves down with a treaty.
Hostilities "As soon as possible" was not feasable without the larger partner, the French, and "ASAP" turned out to be May 1940
However, both British and French governments had other plans than fulfilling the treaties with Poland. On May 4, 1939, a meeting was held in Paris, at which it was decided that the fate of Poland depends on the final outcome of the war, which will depend on our ability to defeat Germany rather than to aid Poland at the beginning. Poland's government was not notified of this decision, and the Polish–British talks in London were continued. A full military alliance treaty was ready to be signed on August 22, but His Majesty's Government postponed the signing until August 25, 1939."
Western betrayal - Wikipedia, the free encyclopedia