The West is angered about Turkey's refusal to go along with it on Iran sanctions, but unlikely to try to punish Ankara as it needs help with neighbouring Syria, say analysts.
While Washington and Brussels are ardent supporters of sanctions to force Iran to abandon its contested nuclear programme, Turkey believes tough measures will backfire and instead backs the policy of engagement and diplomacy.
Turkish officials have refused to join the latest US and EU sanctions against Iran, which include a ban on oil imports, and are only bound by UN Security Council measures.
But analysts said that while Turkey has come pressure from Washington, it will be protected from its wrath largely because of the Syrian crisis on its doorstep.
"First of all, the Obama administration needs Turkey's help in contending with the Arab political uprisings, especially the difficult situation in Syria," said Barbara Slavin, senior fellow at the Atlantic Council of the United States.
Since the outbreak of the uprisings in mid-March last year, Ankara and Washington have been coordinating policies on how to respond to President Bashar al-Assad's deadly crackdown on dissent which has claimed over 7,600 lives according to UN estimates.
Both have called on Assad to step down, and also worry the unrest could deepen in a region already jolted by last year's Arab Spring uprisings.
Indeed, the Turkish government "is taking the opposite side from Iran on the Syrian crisis," said Slavin.
As Syria's closest ally in the region, Iran has stood behind the regime in Damascus while Turkey accused it of "mercilessly murdering" its own people.
The unrest in Syria is not the only divergence in Turkish-Iranian ties.
Ankara's decision to allow a early radar system to be stationed on its soil as part of a NATO missile defense scheme is another source of tension in the two neighbours' relationship.
Turkey, a member of NATO since 1952, has insisted that Iran is not target of the radar but Turkish pleas fell on deaf ears in Tehran which warned that Ankara's consent would create tension and lead to "complicated consequences."
Turkish willingness to get tough with Syria's brutal crackdown and to host NATO radar system on its soil have proved Turkey is still anchored to the West.
Only two years ago, a Turkish veto of a UN Security Council resolution calling for tougher sanctions against Iran shocked Washington, rekindling debates over EU hopeful Turkey's East-West orientation.
At the time, many pundits accused Turkey of drifting away from the West as Ankara had preferred to stand behind a nuclear fuel swap deal it forged with Brazil, despite massive pressure by the United States.
As suspicions have grown over Tehran's nuclear ambitions since then, the regional unrest caused by popular uprisings against authoritarian rulers turned all political calculations upside down and caught many unprepared, including Turkey.
The new quest for freedom in the region pushed Ankara to revisit its policies and drop its once famous zero problems foreign policy with its neighbours.
Turkish leaders won Western plaudits for their outspoken calls for regional dictators to go -- Egypt's Hosni Mubarak, then Libya's Moamer Kadhafi and lastly Syria's Assad.
Still observers say new strains as result of the Arab Spring and NAT0 missile scheme are unlikely to dent Turkish-Iranian trade ties given Ankara's dependence on oil and natural gas imports from Iran.
"The Turkish economy is booming and needs cheap sources of energy to maintain its growth," Joseph Hammond, country editor and analyst for The Oil and Gas Year, told AFP.
Last year its imports of all goods from Iran totalled ê12.5 billion (9.5 billion euros), with much of this due to rising Turkish demand for Iranian energy, according to the February report of the International Crisis Group.
While abiding by UN sanctions, the government here has bolstered trade with Tehran for "pragmatic reasons," said the report.
With one fifth of its natural gas and one third of its oil coming from Iran, officials argue that the impact of a boycott on Iranian energy on the Turkish economy is far greater than on the West, it added.
"In the near future there is little hope Turkey could move rapidly away from Iran as a source of hydrocarbons," said Hammond.
However this is unlikely to jeopardise Turkish-US alliance, according to Slavin.
"The US understands that Turkey does not want to have to rely even more on natural gas from Russia and that Iran is the only practical alternative right now," she said.