When times are good, and the world-economy is expanding in terms of new surplus-value produced, the class struggle is muted. It never goes away, but as long as there is a low level of unemployment and the real incomes of the lower strata are going up, even if only in small amounts, social compromise is the order of the day.
But when the world-economy stagnates and real unemployment expands considerably, it means that the overall pie is shrinking. The question then becomes who shall bear the burden of the shrinkage – within countries and between countries. The class struggle becomes acute and sooner or later leads to open conflict in the streets. This is what has been happening in the world-system since the 1970s, and most dramatically since 2007. Thus far, the very upper strata (the 1%) have been holding on to their share, indeed increasing it. This means necessarily that the share of the 99% has been going down.
The struggle over allocations revolves primarily around two items in the global budget: taxes (how much, and who) and the safety net of the bulk of the population (expenditures on education, health, and lifetime income guarantees). There is no country in which this struggle has not been taking place. But it breaks out more violently in some countries than in others – because of their location in the world-economy, because of their internal demographics, because of their political history.