I definitely think that the US acted alone on D-Day. I think that if other Countries were involved it went have been more calculated and would have gone much smoother I also less US soldiers wouuld have lost their lives. If other Countries would have been involved I think it would have come out a long time ago.
If the United States Armed Forces acted alone during the Invasion of Normandy, which is known as D-day, There's no way they could have liberated France from Germany. That's why it's called the Allied Invasion of France, not U.S. invasion of France. The Allies helped each other to liberate France.
Though events may appear to indicate the contrary, in truth, no country acts alone in war. Whether or not there is open agreement between two or more nations, the fact is that any war is so conspicuous that the sentiments of uninvolved nations are certain to be strong, and their support available, once action takes place.
I do not think that America acted alone on D-Day. I think that while they took a great hit during D-Day and suffered many casualties, I think there were other countries who should be honored for their part as well for their sacrifice. Regardless, it was a day that people should remember.
What happened on Normandy Beach was a combine effort from all of the allies. Even though many movies and other stories from that day seem to paint the effort as strictly American, there is a massive amount of evidence to the contrary. Britain played a very large role possible even greater than the American role.