I think there are many triggers that could see us heading into a really bad time in the near future. What amazes me is the fact that none of them have already tipped the economy upside down. I think governments around the globe are working very hard to pull the wool over their citizens eyes in regards to the true state of economies.
What about:
Energy: the whole economy needs cheap energy to function. Nothing substantial happens without oil, gas, or electricity. We saw how $147/barrel oil devastated the economy. There are geopolitical and competition squeezing forces that mean the pricing of energy is being suppressed currently. The investment in bringing new sources online isn't happening whilst the price is lower, that's going to bite hard at some point.
Confidence in the dollar: The US is in a really bad position and the likes of China, India and Russia know that. China has been stockpiling gold like grazy and selling treasuries too. It might take longer than some think for the US dollar to come under real pressure but one, two or three years isn't much different when the end result is as catastrophic as it will be. I can see the US losing a third of their wealth and importance on the world stage in the space of a small period of time once the run starts.
Unfunded liabilities: The US and many other countries (UK is a prime example too) have a huge amount of obligations that are now coming due as a glut of people retire. Social Security and National Insurance are not big pots of money, state retirement/healthcare payments etc are met by current taxpayers (of which there are fewer than hoped and many have poorly paying jobs). Oh dear.
Interest rates: Governments can't affort to pay anything above almost zero on the huge debts they have, and housing markets are relying on low rates. What happens if rates are forced higher by a lenders strike? You could say that's happening already (and where Quantitative Easing comes in), but that just leads to inflation when the public catches on to the con. No recovery in sight whilst this stays the same.
The western world is goosed, and we haven't even started counting the cost of the disruption to weather that we're seeing. Revolutions start when food gets expensive (relative to income, so western economies have not see it). The Arab Spring and other unrest is often tied, to some degree to food prices, if you pay half of your income to eat and prices double, what do you do? Climate change is set to disrupt the growing of crops in a big way... oops.
I'm not optimistic by the way.
