Any large eruption of VIE 8 in Yellowstone would disrupt the world we live in seriously. A sort of nuclear winter will be the result with lonmgterm effects on the worldwide climate, resulting in mass extinction of many spieces all over the planet.
Humanity as a whole will survive, as it is addaptable to all sorts of dissasters, but the population will be reduced severely, as food would become a major problem, due to the shift in the climate.
Geographically the close proximity to the epic center of the blast will result in direct death of all living things in about a radius of some 1000 km due to both the blas itself and the enormeous amount of debris expelled all over this erea. Nothing can survive this as Volcanic Ash is steril and nothing can grow on it for many years.
Further away the major agricultureregions of the USA will collapse, due the the volume of ash comming down on it, reulting in cropsfailure for many years and shortages in basic foods and so on. Outside the USA, the whole of Northern America will be affected seriously with serious problems in getting crops grown and cattle survival. Europe, Africa, Oceania and Asia too will see problems related to lowering temperatures and climatechange, as a result of the amount or debris in the atmosphere, resulting in a drop in temperature, resulting in agricultural problems on a massive scale.
Socially the developped world will likely see foodriots and wars breaking out for the remaining resources of life (food and water), while the non developped world will most likely see massive famine and starvationproblems, resulting in a serious drop in global population. In the global ballance of power, all states will become likely selfcontainign and global trade will drop to a standstill most likely. The USA will be finished as a global power, due to its own problems in getting alive as an entity, while the remainign powers will seek solutions first focussing internally.