Actually, most of my international relations professors tend to disagree. And there is a huge amount of literature that points out that bipolar system was probably much safer for international stability, than unipolar or multipolar for a long run.(nice summary[1])

The general idea is that unipolarity is anarchical and that it will always try to produce a competitor = lots of wars to come, while in bipolar system you always have 2 strong competitors and it is in theirs interest to stop any local conflict before the second superpower uses it in its advantage. Today it is a complete different story where everyone is figing for who know what reason and USA doesn't really care to stop anyone and it probably cannot do anything in most cases, because back in the days of the cold war there was fight for power and now we actually have luck of power in most conflicts. During cold war we had a clear understanding who is finghig and major hot spots were actually pretty localized (Korea, Vietnam, Afghanistan), but nowadays look at Syria/Yemen/Iraq/Libya/Egypt (I try to follow international relations daily, but have a hard time to truly understand who is fighting whom at this point)War on Terror, wtf is this, some USA global war? who are they fighting really? Afghanistan? Iraq? Enforcing national interests? Who knows. It actually looks like everyone have this war on terror nowadays and USA was just one of the first to face this lack of power all over the world. Actually I'm really hoping that USA is playing the role of Orwellian big brother with constant war, because the alternative is scary: USA is already not able to control the situation and it is going to get worse, much worse. The unipolar world brought us 3-4 more nuclear powers because no one is playing by the rulls anymore. There is no policemen to enforce those rules. We have North Korea escalation not because they are playing with nukes, but because if the USA allows them to keep the weapon, everyone else will go and create one. And then we will be truly fucked up.

- "The United States has been at war for thirteen of the twenty-two years since the end of the Cold War. Put another way, the first two decades of unipolarity, which make up less than 10 percent of U.S. history, account for more than 25 percent of the nation's total time at war."
- "in 2014 these are the only 11 countries in the world that are actually free from conflict" [2]

And if you look at [3] you can see that starting from late 70-s - early 80-s (because that's the time SU started to loose power) we have a spike in number of local conflicts worldwide and there are lots of brutal massacres in 90-s+. Most of the conflicts are in ongoing status for 30-50+ years now and we can see the rapid increase in deaths [4].

I'm not saying that it is 100% correct, most of this is just a theory and everything can change in a matter of 1-5 years, but we still have to see the emergence of new rivals of the USA hegemony and the worst case scenario is the comeback to the multipolar world of 18-19 centuries, but with everyone having nukes and who knows what else.

[1] https://en.wikipedia.org/wiki/Polarity_(international_relati...

[2] http://www.independent.co.uk/news/world/politics/world-peace...

[3] https://en.wikipedia.org/wiki/List_of_wars_by_death_toll

[4] https://en.wikipedia.org/wiki/List_of_number_of_conflicts_pe...