WASHINGTON - A pontoon bridge that serves as a border crossing between Iraq and Syria underscores the rivalry between Kurdish factions that are fighting a common enemy in Islamic State but have simmering disputes that raise concerns about their ability to cooperate in the future.

Since its opening in 2013, the Semalka border crossing over the Tigris River in the village of Faish Kabour has been closed down completely three times, and Kurdish Regional Government restrictions on the Iraqi side regularly limit the crossing of leaders from the Syrian Democratic Forces, along with journalists and some goods like power generators and equipment needed in the rebuilding process.

The Kurdish Democratic Party (KDP) has used the border as a tool for political pressure on its historical rivals that dominate the Syrian Kurdish region, said Michael Rubin, a former Pentagon official who is now an analyst with the American Enterprise Institute in Washington.

“The blockade of Rojava is nothing new,” Rubin said. “When I was in Rojava in 2014, it was ongoing. What the blockade shows, however, is the Kurds' Achilles' heel: For the KRG [Kurdistan Regional Government], everything is about internal Kurdish politics. Even the defeat of ISIS [Islamic State] is secondary to maintaining the upper hand politically.”

“What they do not seem to realize is that they are undercutting themselves: The YPG [Kurdish People's Protection Units] has won public glory in its fight against ISIS. The KDP peshmerga may be doing well now, but its initial retreat from Sinjar - leaving the Yazidis unarmed to their fate - is something which continues to blight their public perception. Now that they seem to be undercutting the YPG, they just come off as bitter. Ultimately, however, the YPG has shown that it can survive the blockade,” Rubin added.

The KRG opened the crossing to break the siege on the Democratic Union Party (PYD)-controlled region in Syria which borders Turkey from the north, ISIS from the south, and Syria’s government from the west. The bridge has facilitated limited trade between the two regions while 300 people are allowed to cross using a boat run by border authorities in Iraqi Kurdistan.

FILE - Residents visit the Kurdish Regional Govern FILE - Residents visit the Kurdish Regional Government (KRG) headquarters in Rabia, northwestern Iraq, April 9, 2016. Critics say that for the KRG, everything is about internal Kurdish politics - even the fight against Islamic State is secondary to maintaining the upper hand politically. FILE - Residents visit the Kurdish Regional Government (KRG) headquarters in Rabia, northwestern Iraq, April 9, 2016. Critics say that for the KRG, everything is about internal Kurdish politics - even the fight against Islamic State is secondary to maintaining the upper hand politically.

Obstacle to building political alliances

Kurdish officials on the Syrian side have complained about the restrictions, saying they are slowing the process of building political alliances to govern areas liberated from ISIS.

“It’s a critical time for Syria and the region,” Ilham Ahmed, co-president of the Democratic Council of Syria, a political front of the so-called Syrian Democratic Forces (SDF), told VOA.

“The SDF is advancing in many areas. Soon the SDF is going to eradicate them [ISIS] from Raqqa.” Ahmad said.

Amjad Othman, the leader of the Reform Movement in Syria, told VOA from SDF-controlled area that he is on the ban list of the KRG.

“I am myself banned from crossing the border. As an official in the Reform movement, we call on all parties not to use the boarder as a political tool,” Othman said. “Many journalists cannot come to report on the war on ISIS, and the services sectors in the areas liberated from ISIS could have been better if the border crossing was not used in this way.”

A KRG border security officer who talked to VOA on condition of anonymity admitted the ban on media, but denied it affected political leaders affiliated with the SDF.

“The security situation in Syria is not safe. This why we are not letting the journalists to come in,” he said, “None of the PYD leaders or the SDF have tried to come via Semalka, and they are not banned from using the border crossing.”

However, media reports claim the U.S. has used helicopters to ferry Kurdish leaders from the Syrian side to avoid worsening tensions.

A U.S Central Command spokesperson declined to comment on the specific reports related to the bridge, referring questions Wednesday to local SDF and KRG officials.

But the spokesperson did encourage all sides to focus on the more important task of defeating ISIS.

“We encourage all forces to remain focused on the counter-ISIS fight and concentrate their efforts on defeating ISIS,” the spokesperson said. “The Coalition continues to work in close coordination with partner forces, including the SDF, the KRG and allies in delivering a lasting defeat to our common enemy, ISIS.”

VOA reached Kurdistan’s Regional Government representative office in Washington for comment on the issue, and in a written statement it emphasized that restricting access to the Iraq-Syria border region does not hinder the fight against Islamic State.

“The Kurdistan Regional Government coordinates closely with our American and Coalition allies in the war against ISIS,” the statement added. “There is war on both sides of the border and access must be controlled to ensure stability. Experienced journalists and humanitarians seeking to travel to Syria are regularly granted access on a case-by-case basis.”