Does it shock you when Brits talks of America being late in WW 2?

They love to say how we took almost two years to come to their aid in WW 2 We did not have mutual defense treaty with them but they did with Poland, two in fact ,last one signed 25 Aug 1939 ''his majesty government would feel duty bound....''' So how long did it take the U k to honour their treaty? How do you think the Poles felt when the British allied with Russia one of the two countries that invaded them?