"American unilateralism is a challenge for Europe on most every level. Washington has more interest in punishing Moscow and less interest in safeguarding Europe's economic wellbeing," Bremmer said.
Coping with China's slowdown
Moving away from geopolitics, China's shift towards slower, more sustainable growth will prove challenging for several countries reliant on commodity exports to the mainland namely Brazil, Australia, Indonesia and Thailand.
The world's second largest economy is expected to grow around 7 percent in 2015, down from an estimated 7.4 percent last year.
The greatest pressure may be in politically unstable Thailand, Bremmer said, where weaker demand in China will weigh on economic growth prospects that will in turn undermine the ruling junta's legitimacy and increase pressure to return the country to democracy.
New weapon of choice
The U.S. will increasingly engage in the "weaponization of finance" - the use of carrots (access to capital markets) and sticks (varied types of sanctions) as tools of coercive diplomacy – to exert its influence over global outcomes.
"Access to the U.S. marketplace and U.S. banks, and Washington's ability and willingness to use them, are becoming more important as instruments of foreign and security policy," Bremmer said.
"In the background looms the ultimate threat: that the United States will financially isolate rogue states by severing their access to capital and the infrastructure used to clear payments. Risks of miscalculation and unintended consequences are high, because use of these tools is new and Washington is learning how they work by trial and error," he said.
While Islamic militant group ISIS faces setbacks in its core bases of Iraq and Syria, its power remains significant and will spread throughout the Middle East and North Africa.
ISIS will set up new units in Yemen, Jordan, and Saudi Arabia, and will inspire many jihadist organizations to join its ranks, said Bremmer, noting that Ansar Bayt al Maqdas in Egypt and Islamists in the Libyan city of Derna have already pledged allegiance to ISIS leader Abu Bakr al Baghdadi.