By Hiwa Osman BBC regional analyst

The agreement between the two main Kurdish parties in Iraqi Kurdistan to resolve their differences is largely seen as a response to international and regional factors in the crisis over Iraq.

Leaders of the Patriotic Union of Kurdistan (PUK) and the Kurdistan Democratic Party (KDP) have created a new unity, signing a pact to commit themselves to a future democratic Iraq.

The PUK and KDP have agreed to resolve their differences

The timing of this - as the drums of war against Iraq beat louder - coincides with the Kurds of Iraq gaining more prominence on the US agenda as key players in a campaign.

But their neighbours, Turkey and Iran, seem to be concerned by the prospects of any Kurdish role in the campaign.

Kurds could either be a participating force or their region could act as a safe haven for refugees fleeing from the rest of Iraq.

Both scenarios are seen as paving the way for a strong Kurdish say in post-Saddam Iraq, as Iraqi Kurds are the only organised opposition group on the ground and have been in control of two-thirds of the Kurdish region outside the control of Baghdad since 1991.

Kurdish 'threat'

The remaining oil-rich third is still under Baghdad's control and is being systematically Arabised.

Iraqi Kurds are protected by no-fly zones enforced by the US and the UK

In a post-Saddam Iraq, the Kurds aim to remove all traces of this Arabisation campaign, formulate a federal system and take part in government in Baghdad.

Apart from not wanting a war on their borders, Turkey and Iran are wary that a strong Kurdish element in Iraq will set an example to their own Kurds, who have been demanding cultural and political rights.

Washington's concern over a strike against Baghdad is that it could pave the way for Turkish and Iranian intervention.

Turkish concern

Turkish officials have expressed their country's concern about a US-led strike against Baghdad, as it could pave the way for "new formations" in Iraq, an act that the Turkish defence minister considers a justification for intervention.

Turkey has two ready-made pretexts to intervene... the Turkomans and the PKK

Kurdish official

This rhetoric has caused increased tension between Turkey and the KDP, whose area would be invaded if Turkey decided to intervene.

The Turkoman Front is a group based in the region and enjoys the strong backing of Ankara, which has repeatedly said that the Turkomans should also have a share in any future deal in Iraq.

"Turkey has two ready-made pretexts to intervene," said a senior Kurdish official who wanted to remain anonymous. "The Turkomans and the PKK."

Remnants of the PKK (now KADEK) fighters, the main Kurdish opposition group in Turkey, are in Iraqi Kurdistan.

Iranian influence

Iran, which entered into an eight-year war with Iraq in the 1980s, has historically supported various Iraqi opposition groups against Baghdad.

Kurds back a US action against Saddam

A new hard-line Islamist group emerged in the region last September and controls a strip on the border between Iran and PUK territory.

The group - Ansar al-Islam - has proved to be a security headache for the two Kurdish parties, especially the PUK.

Sources in the region say that the group has links with al-Qaeda and enjoys the backing of Iran in facilitating their movement and outside access.

Another main opposition group that enjoys Iranian support is the Supreme Council of the Islamic Revolution in Iraq (SCIRI) whose fighting force is regarded by many, especially Turkey, as part of the Iranian armed forces.

Wider conflict

A successful US-led military action against Baghdad could bring Iran's long-time enemy, the US, to its border.

To counteract this, Iran would encourage Ansar al-Islam to attack the Kurds and distract them from taking part in the US-led campaign.

It would also push for its ally, SCIRI, to have a presence on the ground.

Turkish officials have communicated to the Kurds and the US that they would regard military intervention by SCIRI as an Iranian action and that they would also intervene militarily.

These regional threats of intervention, the fast-running clock in Washington, and four years of talks after their earlier agreement in Washington, have put the Kurds under more pressure than ever to be united in the face of all looming scenarios.