Where in Illinois? Don't you think that matters?
From Chicago to Kabul (Kabol):
11,200 km (plus or minus 10 km), or 6957 miles (plus or minus 6 miles). That's over the surface of the Earth. Go through the middle of the planet you could shave off a lot of distance. Trvelling by airplane adds a bit on, as the airplane travels an average of 4-5 miles above the planet, adding to the arc distance.
From Chicago to Kabul (Kabol):
11,200 km (plus or minus 10 km), or 6957 miles (plus or minus 6 miles). That's over the surface of the Earth. Go through the middle of the planet you could shave off a lot of distance. Trvelling by airplane adds a bit on, as the airplane travels an average of 4-5 miles above the planet, adding to the arc distance.