It is the geography, comrade. The roads are straight, because it is all flat like the parries provinces of Canada. Just great plains. No jungles like Vietnam, no hills and mountains like Korea.
No place to do an ambush, hit and run style, lol.
Actually, I-raq was all flat too, but they still managed to do the ambush with the IED.
They were able to do that because the people who planted the bomb melted back into the civilian population.
Here in the Ukraine they cannot do that, because there are no people.
Also, there is too force coming at them at the moment. They should surrender.