Both Russia and China have, both past and present, too many potential problems within their own borders to successfully expand, or even look outwards, that's the price of repression.

"For example: Spain, Holland, Great Britain, Portugal, Japan, Italy, France, Germany....these were all nations with a relatively small amount of land and a high density population...and their history shows that they all set out aggressively at one time or another to establish empires far from home."

In the fifteenth century I do not believe that any of the European countries mentioned above would have fitted the description of having, "a relatively small amount of land and a high density population". Even today only 15% of the land available in the UK is built on, and given proper backing and support British farming could still feed the UK.

Of the countries mentioned - Spain, Portugal, France, Japan, Germany and Italy were the only ones who ever set out aggressively to establish empires. The British and the Dutch founded their empires on the basis of trade not conquest. Both the British and the Dutch confronted Spain, the "Super-Power" of their day, in the sixteenth century and they did so at sea. The Dutch for reasons best known to themselves sided with the Colonies during the Revolutionary War, or War of Independence, in 1776 and bitterly regretted it - they damn near lost everything and never again attained a position where they could challenge Great Britain at sea.

The Russians may have built a large Navy it could never, ever have been described as powerful or profficient. It was utterly shambolic and at times extremely comical, in short a joke.