1. Romans 2. The Vikings (mainly because they were one of the few who ever took British land) 3. Britain 4. Nazis 5. US This is obviously for their own times.

perhaps you better set a definition. using an open criteria means that you should be including the mongols, spanish, dutch, russians, portuguese, fench, italians, javans (for their own region), chinese etc.... this kind of question is as broad as it is long.

1)British- Never will a nation dominate the field of Industry, maritime supremacy and commerce in such a manor as what Britain from the treaty of Utrecht in 1707 to the First World War in 1914 2)Romans- Similar in a sense to Britain, for instance, like Britain they never fought aggressive wars 3)Mongols- The galvanisation of a bunch of nomads, which followed and surpassed their Hunic ancestors, in conquering China and Russia is an extraordinary feet. Yet they failed to establish their culture on the other nations, like Britain and Rome did. 4)US 1942-48- The defence budget was around $900 billion, you can by an awful lot of toys with that. Also 1948 was when the Soviets developed their own atomic bomb, from stolen American plans and designs. 5)Naploeanoic France- He may have betrayed the French revolution, yet he brushed aside the great powers of continental Europe, and he would of gotten away with too had it not been for those pesky redcoats. Lopez, the Egyptians were defeated by the Hittites (900bc) and then several centuries if not a millennium later by the Romans. Therefore I wouldn’t put the Egyptians anywhere near this category.

OK heres my take, starting with a definition of power. In international theory, power is taken to mean the degree to which a country can influence events and behaviour, both internally (its people) and externally (other countries) and to effect the outcome of these events etc in its favour, ie the "possession of controlling influence". This power can come in many forms, from military power to economic and cultural influence. If you consider this definition of power I think that the list would have to be 1. USA 1945 - 2004 2. British Empire 3. Roman Empire 4. Mongol Empire 5. Rule of Alexander the Great 6. Soviet Union 7. Ancient Egypt 8. Ancient China 9. Nazi Germany 10.Napoleonic France

“In international theory, power is taken to mean the degree to which a country can influence events and behaviour, both internally (its people) and externally (other countries) and to effect the outcome of these events etc in its favour, ie the "possession of controlling influence". So surely by this logic the British, Roman and Mongolian, Napoleonic empires should be ahead of the US by some distance, as it’s a lot easier to influence the world, as in Britain’s case, when you control a quarter of it..

Actually, the US controls a quarter of the world if we consider it economically. Today the US accounts for somewhere between 20 and 25 percent of the world economy by itself. Further, the US can at least compel every major power in the world to consider their course of action. Even further, during Great Britain's heyday there were other countries capable of projecting force worldwide that were closer to being on par with the UK. There is no country in the world today that can project power worldwide of the same order of magnitude as the US. At the height of its power the UK was not equal to the entire rest of the world. In the years from 1945 to 1955 the United States economically (and by extension militarily IF they had so desired) was equal to every other nation in the world. The US accounted for just under 50% of the world's GDP and 45 to 50 percent of the world's manufacturing capacity for that decade. When you take into account manufacturing capacity that wasn't needed for bare maintenance, the US accounted for something like 75% of the world's industrial military capacity from 1945 to 1950. The UK, as powerful as they were in the 19th centure, never matched that position. Even today the US probably accounts for something like a full third of the world's industrial military capacity. That is, if the US industry were to be fully mobilized for military purposes and bare maintenance of the civilian sector. The problem with the discussion (in another thread) of how the emerging nations like China and India are growing their economies is that even with the incredible growth they have had, the vast majority of their industry and economy is devoted merely to maintenance, and CANNOT be diverted to military needs without destroying their economy. From an international power perspective that is a surefire recipe for loss of position. If you don't think so, study the economic vs. power potential scenarios of Spain, France and Germany over the course of 1500 to 2000. Or what happened to Britain when she was forced to divert a much larger portion of her economy to the military than she had historically during the period 1910 to 1945.

true, and in todays more globalised and smaller world, economic power is very big key factor in determining a nation's influence.

In a sense America does control the world outside China and a few rogue nations. In fact the military expendature of the United States TODAY equals that of the entire world combined. However in 1945 they really had the chance to officially own the world, if they were ruthless enough they could have done it. Patton wanted to go right through the Russians after the US defeated the Germans and they damn well could have since they had the monopoly on nukes. Imagine a truly democratic Russia at that time minus a few cities, Mr. Mao would have never came into power in 1949 had the Soviets been defeated prior to this date. Hell it would have been just like the federation in starship troopers world government everybody cooperating as one. Of course you would still have pesky old Islam, but the new federation would be united in combatting its evils.

"Patton wanted to go right through the Russians after the US defeated the Germans" im sorry, i object to that termanoligy. the US did NOT defeat the Germans single handedly... but i'm sure that's not what you ment... as for the question at hand... 1: USA, post '45 2: Rome, at the true hight of it's power. 3: The British Empire after that i'm not sure... but if i had to continue the list i'd have, (in no order), Napolionic France, Mongols, Nazi Germany (1940 - 42) and ancieint china.

mike_golf makes my case well. Control does not have to be about just direct control. The old Empires from British to Roman, were about controlling territory and resources. The territories within the Empire were an extention of the state and its people, subjects of that Empire. Following 1945 the idea of these collonial empires (essentially mainifestations of a nations power and influence)was reversed, and over the next few decades the collonies of Western Europe either won or were given their independance. One of the key reasons for this fall of Empires was the fact that America insisted on it. Rooservelt told Churchill early on in WW2 that ultimately Britain and the rest of Europe would have to give up their Empires. My point is that once the manifestation of power was a territorial Empire. Not anymore. America rewrote the rules. If you could translate the power of the USA today, into an ability to have a territorial empire, it would out strip that of the British Empire, the largest Empire to date. Another very important point already made, is the difference in power parity between the USA and the rest of the World. Now that we are in a unipolar World with the collapse of the USSR the US is the most powerful state on earth by several magnitudes. At no time in history has one power been so clearly above all other powers. The British, Roman, Mongol, Napoleonic etc Empires have all enjoied status as the most powerful nation on earth in their time, but their competitors, though behind them in power, were always closer in power terms to the top dog, than any nation is today. The US is at no.1 in my list because never has there been such a big gap between the most powerful nation on earth and everyone else. America influences the world with its huge military, but also ist huge economic power, it has far more MNC's than any other state with which to assert economic influecne. There is also power of Hollywood and MTV and the internet etc American influence saturates almost all aspects of global life. In many ways globalisation is Americanisation. Americans Empire is much more dangerous beceause go can not see it. It is not defined by territory, but by how many other countries around the world watch its media, buy its goods and rely on its companies to invest in their economies and provide jobs for its people. And if you dont want to buy into the American dream? Well theres alway the most potent military force in all history to make sure that any rouge states tow the line.