US will remain the world's sole superpower.

1. US competition with EU - US GDP growth rate remains far above that of the EU. The gap between the US economy and the European Union economy will only grow with time.

2. US competition with China - China's GDP growth has slowed down enough and is continuing to decline to the point that they are going to end up the way of Japan and South Korea. China is well positioned to fall into the middle income trap. After days of research one can conclude that the gap between the US and Chinese economies is going to increase in the coming decade. With China never catching up to the US economy.

3. US competition with India - India started off too late in the race. It would take 20-25 years for it just to become a middle income economy. India would have started to go the way of East Asian economies by the time it becomes a developed economy. With the US at that point in time still ahead of the Indian economy.

4. There are no other economies in the world large enough to compete with the US.

5. US, EU, China, and India, together in the coming decades would hold 75%-90% of the world's GDP. The US would be growing at a consistently faster rate than these economies when they peak.

6. Taking all these factors into account, the US will be the singular dominant super power of the world this century.