Arguably the longest standing, nastiest, most irrational US foreign affairs policy is Cuba.

In part this is for domestic reasons - a powerful Cuban expat community. But in another sense it is that Cuba is the most instrangient nation inside what the US considers its most important sphere of influence - Central America and the Carribean. Cuba is very, very close to the US mainland, as the Cuban missile crisis showed - potentially dangerously close.

Much of the American nineteenth century (and to a lesser extent, the twentieth), in foreign policy terms, can be viewed as the US gaining a normal great power sphere of influence in its geographic proximity - first pushing out the remains of the Spanish empire, and then making it clear to the successor states that if the US didn't like what they were doing, the US would quite happily punish them, up to and including invasion.

The Monroe doctrine was a formalization of the US attempt to push out its sphere of influence:

the United States was informing the powers of the Old World that the American continents were no longer open to European colonization, and that any effort to extend European political influence into the New World would be considered by the United States "as dangerous to our peace and safety." The United States would not interfere in European wars or internal affairs, and expected Europe to stay out of American affairs.

Every Great Power has its sphere of influence and outposts. Super Powers (or hegemonic powers) like the US currently, the USSR during its day and Britain and Spain during their heydays, have spheres of influence that extend throughout the world.

That brings them into conflict with other nations, especially with the Great Powers of the day.

Sphere's of influence expand to areas where a nation believes it has a primary interest, whether economic or military. The Strait of Hormuz is an area the US and Iran clash over because it controls the flow of oil. Korea is a strategically important area because of it is a transhipment point between the Americas, China and Japan from which any of the three can be struck. The nations around Russia are considered important because Russia is flat and impossible to defend without having defense in depth (ie. land to fall back into.)

A large number of Russia's current actions, from selling Venezuela small arms and Syria air defense; to landing airmobile troops in Serbia; to refusing to allow censure of Syria over the Harriri affair are a reaction to the US and European invasion of what Russia considers its sphere of influence.

Ever since the nineties, and peaking with the Ukrainian Orange Revolution, the West has been encroaching into Russian client states. It has expanded Nato far into the east. It has built bases in the various Stans... and it spent many millions and sent in large numbers of organizers into the Ukraine to ensure that the pro-Western (and anti-Russian) side won.

From a Russian point of view, America, and a resurgent Germany backed by the EU and Nato, have been pushing deeply into Russia's sphere of influence and threatening Russia's ability to defend itself. Nato expansion cannot be seen as anything but a threat to Russia (who else is Nato going to defend those nations against?) Likewise it has always been very clear that the US's expansion into the ex-Soviet Republics of the east was aimed largely at securing their oil reserves, with the eventual goal of a pipeiline and extraction the west. As such the Russians cannot but view it as a threat to them both in terms of military positioning and economic positioning.

Russia has, as a result, stuck a thumb in the US's eye whenever it reasonably could. The recent flexing of oil muscle to both the Ukraine and Germany must be seen in this light. "We have something you need, and you can't do anything about it, so perhaps you ought to stop pissing us off" was the very clear message.

Recall that the Germans main strategic goal during the Russian invasion of World War II... was the oil fields past Stalingrad.

When the USSR collapsed pundits (and fools) talked of a unipolar world and the "end of history".

What has happened, and is happening, instead, is that nations like China, Japan, Iran (Persia) and Germany are reasserting their traditional spheres of influence. As the US moves into full Imperial overstretch - as it becomes clear to countries like Japan that the US won't, or can't, be trusted to protect them - spheres of influence have rippled into being and a cold (and occasional hot) contention over them has begun.

And as China pushes firmly beyond the regional power status of countries like Iran, into great power status, China is pushing their sphere of influence out to the Middle East (they are a significant patron of Iran) and into Africa (Sudan, as an example.)

China, in fact, is offering the same thing that the US did during the early nineteenth century to those outside its near sphere of influence (ie. Taiwan doesn't get this deal.)

"We will support you against the hegemonic power and all we ask is that you sell us your goods and not allow them to use you as a base against us."

Which is to say - China says to nations like Iran, "we won't meddle in your internal affairs the way the US does. All we care about is if the crude arrives on time - and we'll pay top dollar for that, and not tie our technological aid and money to political change."

Then there are American client states. Places like Japan, which are realizing that they can no longer be sure the US will protect their interests. If Japan, which is completely reliant on sea lanes remaining open, wants to be sure it is safe, it will be forced to expand its sphere of influence. If it wants its share of underwater oil, it will be forced to contend with Russia and China for it.

In the affairs of Empire, as with the affairs of men, when the most powerful player begins to show signs of decline, the lesser powers jockey for power. That is the era we are entering now, where Great and Regional powers jockey for position, and where sphere's of influence are not settled. Russia seeks to reclaim theirs. Iran seeks to reestablish the traditional Persian sphere of infleunce both to its west and its north (they are very powerful in Afghanistan). China seeks to bring its rebellious province back under control to push its sphere out to resource colonies and to bring Japan and Korea firmly into its sphere, rather than allowing them to form in opposition. And the US, seeking to maintain the flow of oil it needs for its economy, struggles to maintain the Middle East Raj it inherited from the British, and to swallow as much of the old near Russian sphere of influence as it can. Meanwhile, a resurgent Europe - and a resurgent, unified Germany - have found that the old oil weakness that doomed Germany in the forties is still a factor today.

Great powers rise, and Great powers fall, but the Great Game... is eternal.