Let’s start from demography. During this decade, world population increased from 6,9 to 7,7 billion people. The average growth rate continued to decline as predicted but anyway, if you think about, these numbers are amazing. Another, truly symbolic milestone: for the first time in human history, urban population outnumbered the rural one. By the end of decade, the population of “world city” reached roughly 55% while “world village” shrank to 45% and this trend will continue.
There were no major interstate wars and territorial changes, though with two important exceptions: South Sudan seceded from Sudan in 2011 and became a fully recognized country and a new UN member. Crimea seceded from Ukraine in 2014 and re-joined (or was annexed by) Russia. Unlike South Sudan, this event wasn't recognized by UN.
Among the main events that shaped the face of the decade, one can mention the “Arab Spring” supposed to pave the way for liberal democracy in the Middle East, but in reality paved the way to instability and a long chain of bloody and complex conflicts with tens of participants including great powers. The main victims of “Arab Spring” were Libya (regressed from stable and relatively advanced dictatorship to failed state and boiling pot of warring factions), Syria (large-scale civil war that had a huge impact on current world order), and Yemen (Saudi invasion, that was supposed to be a “small victorious war”, has led to long and hopeless conflict with Houthis - the local religious/patriotic movement supported by Iran).
Another Middle Eastern sensation was the spectacular rise and fall of ISIS – the first real attempt of "international terrorism" to create its own state from scratch. Attempt has failed (or, to be honest, was crushed by mutual efforts of few competing great powers) but caused a huge damage to the entire region.
In the West, the main trend of the decade was erosion of stable and (as it seemed) long established bourgeois democracy and the rise of “anti-establishment” movements and politicians. Very different (from ultra-left to ultra-right ones), these movements had one thing in common: they have grown from fear and anxiety of “little man” faced with advancing neoliberalism and declining welfare state. The neoliberal mainstream is still refusing to acknowledge and respond to these anxieties and describing them as a mere riot of "ignorance and bigotry" against progress and common sense. In any case, one thing is now obvious: the predicted and long awaited (by Western elites) “End of History” not going to happen in the foreseeable future.
Another main trend was a slow decline of US hegemony and ability to “project power” on others. Failures in Syria (inability to change the “regime” backed by competing great power) and Venezuela (the "winner" of the coup was proudly and openly announced and "recognized", but then...) were especially symbolic and indicative. As recently as in the early 2010s, Americans were busy discussing the pleasant matters like: “are we a hyperpower or just a superpower?” By the end of 2010s, they’re discussing the matters like “are we really a failing state?” In the forming multi-polar world, America will, for some time, still remain “strongest among equals” but far from undisputed world leader it was in 1990s or 2000s.
My Country (Russia)
During 2010s, Russia remained itself: a country of striking contrasts, the slowly (or not so slowly, in this decade) advancing cyberpunk coexisting with slowly retreating, but still viable archaics. Existing political regime reached maturity, the word “stability” replaced the word "reforms" as a symbol of desired state of things. Unlike 2000s with their booming economy, 2010s became the decade of geopolitical adventures and economic slowdown. Russia continued to evolve towards state-monopolistic capitalism. The share of state in economy has risen dramatically while small business is (in best case) still struggling for survival.
But this “stability” is clearly coming to an end. Russian society, too, reached maturity and feels a growing discomfort from rigid bureaucratic paternalism with its desire to control everything that can be controlled and strangle everything that can not be controlled. As it was said above, the 2010s were the decade of geopolitical adventures which have merged the common people and elites into brief situative alliance called “Crimean consensus”. But in 2018, elites themselves destroyed this “consensus” with their cynical and ill-prepared pension reform.
Other important failure of current regime is its inability to offer the viable and attractive ideology. And what was really offered – the new edition of quasi-religious and quasi-monarchic ideas, combined with castrated and carefully managed state patriotism – instead of source of inspiration became rather a target of jokes. And this is logical: what worked well for XIX century peasants, can not work the same way for XXI century urbanites.
The present is controversial, the future is foggy. But situation is far from being hopeless. There were also important victories, achievements, great infrastuctural projects that will be remembered by descendants. Though not so fast, our life is getting richer and longer, our cities are becoming cleaner and safer. The legendary “Russian alcoholism” has long become a thing of past, and street crime is ceased to be even mentioned as one of public concerns.
My City (Samara)
I have no reasons to complain. The city is growing, qualitatively and quantitatively. Within 2010s, we’ve seen one new river bridge, few new highways, two new satellite towns, upgraded embankment, a world-class football stadium, and so on... in general, Samara has become cleaner, more modern and comfortable. I hope this trend will continue.