BEIRUT (Reuters) - The weakness and wealth of Iraq, now shorn of all but 50,000 U.S. troops, tempt its anxious neighbours to vie for influence among Iraqi factions struggling to form a government nearly six months after an election.
Iraq's fledgling army remains ill-equipped to defend the national borders, but for now Iran, Turkey, Saudi Arabia and Syria are pursuing their goals mostly by non-military means.
None can count on getting the upper hand.
The 2003 U.S.-led invasion empowered Shi'ite Islamist groups friendly to Iran, but intra-Shi'ite conflicts, assertive Shi'ite politicians and core Iraqi nationalism limit even Tehran's sway.
Turkey, using its growing regional influence, diplomatic reach, economic power and new popularity in the Arab world to act as a soft-spoken counterweight to Iran, advocates bringing Sunnis and Kurds, as well as Shi'ites, into any new government in Baghdad.
Although the U.S. combat mission ends this week without an agreed Iraqi government in place to check spurts of violence, adjacent countries seem less inclined to revive the widespread bloodletting that threatened to consume Iraq a few years ago.
"In 2005, Iran, Syria and Saudi Arabia were all feeding the violence in Iraq; the United States was adrift without a strategy; and the Iraqi government and security forces were barely existent," said Eurasia Group analyst David Bender.
Today, he argued, those neighbours preferred stability in Iraq, Iraqi security forces had improved and the viability of the Iraqi state was not being threatened as it was in 2005.
Even patchy progress in state-building, almost from scratch after the United States removed Saddam Hussein, banned his Baath Party and disbanded the army, has helped cap outside meddling.
"The stronger the state in terms of capacity and legitimacy, the weaker the regional factors," said Beirut-based sociologist Faleh Abdul-Jabbar. "So we are in better shape than in 2004-8."
He said foreign powers had to reckon with Iraqi leaders who had gained strength from their grip on the government, the state and its resources. They could not just dictate orders.
Abdul-Jabbar cited Iran's failure to persuade its closest Shi'ite allies to swing behind acting Prime Minister Nuri al-Maliki after the indecisive March vote narrowly gave former premier Iyad Allawi the biggest single bloc in parliament.
"Moqtada al-Sadr and Ammar al-Hakim refused to endorse Maliki, and Maliki refused to join hands with them despite tremendous, unbelievable pressure from the Iranians," he said.
Secular Turkey, ruled by a moderate Sunni Islamist party , looks askance at any line-up that would allow Shi'ite factions to exclude disenchanted minority Sunnis from power -- a scenario that dismays Saudi Arabia and many other Arab countries.
They see a share of power for Allawi, a secular Shi'ite who won many Sunni votes in the March election, as the best way to help reintegrate Sunnis into Iraqi politics to avoid any return to the Sunni insurgency that helped al Qaeda militants flourish.
The Americans, who were impressed when Maliki defied Iranian wishes and attacked Sadr's Mehdi Army militia in 2008, also want an inclusive Baghdad government, perhaps one aligning Allawi's bloc with that of Maliki and a Kurdish alliance.
Personal ambitions as much as political differences have hindered the emergence of any such coalition. Iraq's neighbours also find it easier to block alliances than to forge them.
Even regional allies such as Iran and Syria are at odds over Iraq -- it goes against the Arab nationalist grain of the secular Baathists who rule Syria, a Sunni-majority country, to see pro-Iranian Shi'ite Islamists monopolise power in Baghdad.
Turkey, while pursuing its own interests in Iraq, has avoided antagonising Iran, a valued trading partner, and has sought ways to resolve Tehran's nuclear dispute with the West.
The United States, having upset the regional chessboard by invading Iraq, will see its power wane as its troops withdraw.
"Iran has to a great degree already found its role in Iraq. The U.S. combat withdrawal will allow Iran to entrench that position," said Gala Riani of IHS Global Insight.
Yet political dominance eludes Iran, which has also met resistance from the Shi'ite religious schools in the holy city of Najaf, where Grand Ayatollah Ali al-Sistani, a heavyweight cleric revered across the Shi'ite world, challenges the doctrines of clerical rule that underpin the Islamic Republic.
"Iraq is theologically more important to Shi'ite Islam than Iran," said Paul Rogers, a professor at Britain's Bradford University, alluding to Iraq's great Shi'ite shrine cities of Najaf and Kerbala. "This may tend to limit Iran's religious influence."
For now, Iraq's neighbours are jockeying for political influence rather than pursuing their goals by force.
That could change.
If Iraq's post-election deadlock persists, the greater the risk of its security gains unravelling. Political, ethnic and sectarian groups might eventually abandon the bargaining process and return to violence to secure their perceived interests.
Any such breakdown, particularly if it led to a showdown between Arabs and Kurds in the north, could draw in Turkey, Iran or Syria, which each have their own restive Kurdish minorities.
Abdul-Jabbar said military intervention by Iraq's neighbours could not be entirely discounted, even though it was an extreme scenario made less likely even by a reduced U.S. troop presence.
"But if this stalemate lingers on, if the Baathists decide to go violent again, if the army disintegrates, why not?"
(Editing by Michael Christie)