Vietnam is probably America's most embarrassing war. As stated above, there were possible avenues to achieve diplomatic victory before ever needing to put boots on the ground. Then, after we put boots on the ground, we fought a long, bloody, expensive war for years all the way up the point that leadership in the north was actually getting ready to sue for peace after the Tet Offensive failed. But before they could do that, they saw we were withdrawing and could practically walk on in and seize the south. America never took more Ls in one war than 'nam.