As Western diplomats prepare to resume talks with their Iranian counterparts in Vienna tomorrow, some in the Western media have begun to express anxiousness and concern over the inability of the so-called P5+1 — the U.S., China, Russia, Britain, France, and Germany — to secure an agreement with Tehran on its controversial nuclear program.

However, these concerns, while not entirely without merit, are somewhat shortsighted. The truth is that an Iranian nuclear deal would change very little about the dynamic in the Middle East.

U.S. military supremacy in the region hinges on the cooperation of a predominantly Sunni Arab alliance across the Middle East. Whether it's the U.S. Navy's Fifth Fleet in Bahrain, air bases in Kuwait and the United Arab Emirates, or the crucial al Udeid central command station in Qatar, Washington relies on these mostly undemocratic regimes to carry out its military policy in the region.

The implied quid pro quo of these entanglements is, naturally, a virtual blank check on arms and aid, in addition to a mostly blind eye on human rights.

This, needless to say, is an arrangement that the Iranians have not enjoyed for quite some time. Iran was once considered a "pillar" of American cold-war policy in the Mideast, but the Islamic Revolution of 1979 changed the Mideast balance of power almost overnight. In the years following the revolution, Iran became more and more isolated as it battled its Sunni neighbors for influence.

Perhaps the defining rivalry in this tug-of-war is the one between Iran and Saudi Arabia. The Saudi monarchy has long held Tehran in contempt for its regional machinations, and recent events have done little to assuage the kingdom.

In Syria, Iranian ally Bashar al-Assad finds himself fending off a variety of rebel groups, many of which have received both financial and material assistance from Riyadh. For Iran, the ability to reach its militant proxies in and around the Palestinian territories represents an important piece of its regional strategy. The loss of a friendly buffer in Damascus would complicate matters for Iran's rulers, and at the same time compound the country's isolation — both preferable outcomes for the Saudis.

But this war is not isolated to Syria. A Shiite rebellion in Yemen has put a Saudi-friendly regime in Sanaa in jeopardy, as the Houthis — followers of a divergent branch of Shiism long believed to be armed by Tehran — have seized the capital and are pressing the government for greater autonomy and entitlements.

This battle is unfolding in the world's oil markets too. With oil prices falling, Saudi Arabia is quickly moving to retain its dominance over market share. While the Saudis are well positioned to withstand these relatively modest price fluctuations, Iran, as Foreign Policy's Keith Johnson recently pointed out, is not.

"Iran by far requires the highest prices to remain fiscally sound, by some estimates as much as $130 a barrel," writes Johnson. "Further, Iran has been hammered by Western sanctions that have cut its oil exports — and earnings — almost in half."

And that is precisely where Washington wants Iran: isolated and on the cusp of insolvency. Iranians are not oblivious to this fact, and in spite of their rather cosmopolitan disposition, Iranians overwhelmingly reject U.S. policy toward their country. Indeed, a recent survey conducted by the Center for International and Security Studies at Maryland found that over 70 percent of Iranians believe Western sanctions are designed to punish the average citizen, with most expecting sanctions to increase with or without a nuclear agreement.

Iran's supreme leader, Ali Khamenei, has repeatedly exploited these fears, proclaiming in speeches and written statements that the pressure being applied on Iran's nuclear program represents just the beginning of Western coercion.

"The nuclear issue is an excuse for America (to continue) its animosity. Now, the American spokesmen are bringing up the issues of human rights and missiles," said Khamenei in remarks from earlier this year.

Khamenei's calculated musings tap into long-held Iranian grievances, and it would be naïve to assume that a nuclear pact would do much to dispel such concerns. Even prior to the revolution — when Tehran enjoyed U.S. client state status — presidents from Kennedy to Carter attempted to dictate Iranian behavior, often to mixed results.

No matter who governs Iran, the country will always pursue its own interests in an otherwise unfriendly neighborhood, and a more democratic Iran certainly wouldn't guarantee a more pliant one. This leaves Washington with little choice but to pick a side and act accordingly.

A look at a map of Mideast military deployments suggests that the U.S. has done just that.