Why was fighting in afghanistan was so difficult

Fighting in Afghanistan was so difficult because:

Terrain was almost insurmountable, hard to get around

various tribes and gangs that act as the militia. This is yet another threat to the US

so much lack of infrastructure

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.