To show that something is a global issue, I merely have to display instances world-wide, not in every single country (that's the difference between global/ubiquitous and 'universal').
Having the issue in Africa, North and South America, Europe, and Australia is enough to satisfy that. I'll have to defer to others experiences in Asia, as keeping up with 4 continents is enough for me ;)
Additionally, this ideology expresses itself in different ways per country. The issue of white supremacy in for instance Togo, is not that there are white police officers and segregated drinking fountains. It's that the French forcibly colonized the area, then set up an exploitative trade zone after WW2, and continues to prop up brutal dictatorships merely because the leaders are willing to cede economic control to France. It's that the French are forcing their language & culture on a country as part of a 'trade' agreement (to the point where the government must buy French textbooks), but there isn't any reverse requirement of cultural exchange.
White supremacy is a global issue.
Yet all global issues won't affect every country equally.
Climate change may have global effects, but as the Fins famously said 'we live in the mountains, we will be the last to drown!'.