Basic barrier defense
The Barbed Wire fence is a cheap, simple anti-infantry barrier used by Soviet forces during the Second World War. It is generally effective at blockading only non-demolition infantry and light vehicles.
Barbed wire is a length of steel wire with razor-sharp barbs (thus the name) protruding at intervals throughout it. These wires were often fastened to fenceposts to make barbed wire fences.
During the Second World War, the Soviets made extensive use of barbed wire fencing to prevent enemy infantry from advancing into Soviet lines. Infantry crossing through a barbed wire fence would likely risk severe injuries, and light vehicles would certainly have their tires cut open. While it would be possible for an infantryman to slowly and carefully negotiate his way through the wire, or cut the strands of wire to pass, in the heat of battle this would endanger their lives. Therefore, infantrymen and light vehicles usually avoid barbed wire. However, infantry armed with explosives find that, luckily, their weapons could clear a path through the barricade, and heavier vehicles (such as tanks) could simply crush it under their tracks.
After the Second World War, barbed wire was largely replaced with chain link fence (which itself often had barbed wire or razor wire running along the top), although civilian farmers continue to use the traditional barbed wire fence as an inexpensive way to keep their livestock in check.