USA will not last I am sad to say. Middle eastern countries are going to last MUCH MUCH longer than USA. USA may be a dominant power by 2100, but time to 2200+ it will be in a world of hurt.
The united states uses a ridiculous amount of water everyday, while spending almost the equivalent amount of money per ____ (where ____ is the random factor). Think about how much water you waste everyday and then think of everyone else, more or less, it's almost equal. Toilets flush gallons of fresh water, which could be used for drinking while we wash dishes etc.
Western countries have much less water, but they use it wisely, anything they can do with (i.e. 3 gallons) of water will be done, with only drops wasted.
http://www.actionbioscience.org/environment/kassas.html has an article on water use and statistics about it.
more than half of all people could be living in severely water-stressed areas by 2032
How much water is available?
A new appraisal shows that of the total 1386 million km3 of water (Earth's hydrosphere)2:
* 97.5% is saltwater, e.g., oceans, seas
* 2.5% is freshwater (54.65 million km3)
Now salt water can be converted into fresh water, but at a hefty price... Desalination plants range from $700/AF to $6,000/AF ($700 is an estimated price for a proposed California plant).
Another article at
http://ga.water.usgs.gov/edu/wateruse2000.html shows that
about 408 billion gallons of water per day were withdrawn for use in the United States during 2000.
THAT'S RIDICULOUS! 85% of this water was fresh water. That's 346,800,000,000 gallons of fresh water. PER DAY!!!!!!!!!!!!!!!!!!!!!!!!!!! 79% of this water was surface water while the others were ground water etc. Thermoelectric-power plants took around 195,000,000,000 gallons/day. Do you realize the significance of this?.... This was 6 years ago, the numbers can only go up.
The United States is ranked 4th in the world for population. A CIA July 2006 population estimation shows that the U.S. will have approximately 298,444,215 citizens, not including illegal immigrants etc, this only includes people registered on the census. The United States uses 80-100 gallons of water per person per day. This can be dropped 10-20 gallons per person.
There are many other contributing factors at the moment, but fresh water will be a huge problem soon. Unless [we], the U.S., stop our water outsourcing, we won't last for much longer.
EDIT--
Forgot to say my vote. I voted for Canada, because I'd like to see it happen. But I really think China will be it... or India, because they are freaky with computers, they're gifted.