The global economy will be tied together by computers, a single, unified, global system of computers, a system guarded more carefully than Fort Knox or any number of Presidents. It will be multinationally controlled and constantly patrolled, in various ways, to protect it from special interests and interference by those who would profit unfairly off its control of the ebb and flow of interest rates, tariffs, trade balances, currency fluctuations, and etc. The general trend will be to treat the global economy as intimately interfacing cells of commerce, each one independent and simultaneously each one inter related, a continuously altering but nevertheless consistent model. Because the world is becoming more socially interactive, through all manner of media and vehicular intercourse, it is also more vulnerable, in certain respects.
Terrorists have more recourse, many more options.
Disease has more venues of vector. As population pressures build national borders almost literally high-pressure one another, as nations compete for resources and room, and as illegal immigrants and the growing problem of refugees compound this friction. The balkanization we've seen in Eastern Europe and Africa will continue and spread. More militant black groups will organize and surface, and become active as terrorists, serving as rationale for white bigotry. All of this could fuel the fire of the potential new American Civil War.