The mismatch between strategic intentions and actual outcomes has been a feature of the almost twelve years of the "war on terror". The latest phase of conflict, however, is making the gap ever wider.

In the case of Afghanistan, the termination of the Taliban regime by United States forces and Northern Alliance warlords in 2001 confirmed Washington in its ambition to occupy several large bases in the country and secure new facilities throughout central Asia. In the case of Iraq, the destruction of Saddam Hussein's regime in 2003, whatever its stated motive, seemed to advance the aim of limiting Iran's influence in the region.

Iran, it was hoped, would face US bases to the east, the US navy's fifth fleet to the south, pro-American allies across the Persian Gulf, and a major US military presence in post-Saddam Iraq to the west. For George W Bush and his supporters, a long-standing enemy in the region would be cowed - and the "new American century" would be back on track.

A decade later, Iraq has turned sour for Washington. Barack Obama's administration, having failed to get immunity agreements for US forces from Nouri al-Maliki's government, had little choice but to withdraw all combat troops by the end of 2011. Most of what US influence remained went with them. Washington now faces an Iran-Iraq axis in the region, currently evident in these states' support for Bashar al-Assad's regime in Damascus.

For Saudi Arabia, the effects of the war approach a nightmare. Instead of a pro-western Iraq with thousands of US troops as guarantors of security, Riyadh sees the prospect of a “Shi'a crescent” stretching from the Mediterranean across Syria, Iraq and Iran through to the Indian Ocean.

Amid this bleak picture, Afghanistan has seemed to offer the Obama administration some succour. The US's continued presence in Afghanistan, albeit in the shape of armed drones, special-force operations and privatised military companies rather than large numbers of troops, would protect Washington's interests there; long-term US bases would avert the risk of al-Qaida's reawakening in "AfPak", as well as deterring Iranian influence in western Afghanistan.

True, this was far less than what Washington initially hoped for, but things could be worse. Now, however, that calculation is looking fragile. In particular, it is now becoming clear that US efforts to negotiate a major post-war role in Afghanistan are proving much more difficult than expected at a time of deterioration in the already problematic US-Pakistan relationship. The geopolitical damage could yet be acute.

Between hope and reality

Barack Obama's first-term Afghan policy set a pattern that combined fresh troop deployments, a schedule of phased withdrawals, and plans for contingents to remain in the country after the handover to Afghan authorities was complete. By mid-2013 the Pentagon had reduced US force levels from a peak of 100,000 in early 2012 to 63,000, with a further reduction to 34,000 in train over the period to January 2014. It was anticipated that around 10,000 US military personnel would remain in a mix of training roles, guarding American civilians, supporting drone operations and covert special-forces' combat operations.

This balancing of elements has begun to look less certain. A series of tense discussions between Washington and Kabul is pervaded by suspicion, not least over US moves to start discussions with the Taliban via the latter's Doha office. Hamid Karzai objects strongly to a venture he sees as undermining his own position. Moreover, there are indications that the Obama administration no longer sees a complete withdrawal of its forces as a worst-case option (see Mark Mazzetti & Matthew Rosenberg, “Obama may seek faster Afghanistan exit”, New York Times, 10 July 2013).

A further complicaton is that even if Karzai agrees to US troops staying, he would want one of their key functions to be the control of Taliban and other radical elements conducting cross-border operations from northwest Pakistan. In turn this would risk inflaming the bitter anti-Americanism now evident across Pakistan's political and social spectrum.

An example is the leaking of the Abbottabad commission report on how Osama bin Laden evaded detention in Pakistan for nine years. The report, a damning indictment of the Pakistani intelligence and security communities, also reveals the anger within Pakistan at the perceived impunity with which the CIA and other United States agencies have acted inside the country (see Declan Walsh, “Bin Laden inquiry assails security forces”, New York Times, 10 July 2013).

This impunity extends beyond the US operation that led to bin Laden's killing. It embraces the much wider issue of armed-drone attacks and other infringements of sovereignty: precisely the area in which the Kabul regime wants the US to remain active.

The outcome of all this is that Washington may decide in the coming months to end almost all involvement in the security of Afghanistan, even including the substantial aid promised to support the Afghan national army and other military, paramilitary and police forces. This would inevitably also mean scaling down its ability to conduct operations in Pakistan.

If this does happen - and the chances are increasing by the week - then the result of the wars in Afghanistan and Iraq since late 2001 will prove to have been utterly different in strategic terms to early expectations. In addition to the human cost (some 200,000 people killed, hundreds of thousands injured, and over 8 million people displaced), Iran will have gained regional power at the expense of the United States, and Washington's agency across central Asia will have all but disappeared.

Some will argue that this is potent evidence of Obama's failure; but it may also be a case of his having to act as president of a superpower that wields ever less influence across the world. In the short term he may be castigated for overseeing failure. In the long term, perhaps not, as the verdict adapts to a historic change.