Disputes within families often become the most bitter kind of disagreement. Family members know each other too well, and memories of past slights linger for too long. In times of great difficulty, however, it is usually family that comes forward to help before any outsider lifts a finger. Whatever the nature of the disputes between them, the blood of kin runs thicker than the water of strangers.

The latest crisis brought on by the Islamic State's (IS) offensive against the Kurdistan Region of Iraq seems to demonstrate this quite clearly. When the IS pushed the peshmerga out of Shangal, Zumar, Qaraqosh, Makhmour, Jawawla and advanced to within thirty kilometers of Hawler itself, it was the fellow Kurds of the Kurdistan Workers' Party (PKK) who did not hesitate to come to Hawler's aid. Yezidi civilian had already been stranded on Mount Shangal for some five days before Western states decided to provide some support via air strikes and supplies sent to the Iraqi Kurds, but the guerrillas of the PKK's sister organization in Syria had crossed the border on the first day of the offensive to lend their support to their Kurdish brothers and sisters in South Kurdistan.

By most accounts, the guerrillas of the PKK and its sister organizations from Rojava and Eastern Kurdistan turned the tide against the IS Jihadis. The followers of Apo, you see, have a lot of very recent combat experience. Those in Syria have been successfully fighting the IS and other Jihadis such as Jabhat al Nusra since 2012, on their own without any significant outside support. It was these experienced guerrillas who opened a corridor to Mount Shangal to allow Yezidi civilians to escape the Jihadi encirclement. Likewise in Makhmour, Jawawla and other fronts, it was PKK fighers working together with the peshmerga who took the offensive back to the IS and forced them to retreat.

According to journalists on the ground, the fighters from the PKK and the Kurdistan Regional Government (KRG) worked hand-in-hand in this, getting along well and apparently showing little concern for the political disputes of the past. Indeed, there is nothing like a serious outside threat to unite kin. Past disputes are set aside as the family must struggle to survive. In the first days of the latest war, KRG President Massoud Barzani visited with PKK field commanders near the front to coordinate with them and thank them for their help.

President Barzani no doubt felt vindicated in his refusal, since 2003, to try and force the PKK out of the Qandil Mountains. For years, Turkey pressured KRG leaders to help it attack the PKK in Iraqi Kurdistan. While these kinds of requests from Ankara were sometimes obeyed in the early 1990s, a more confident Mr. Barzani steadfastly refused to permit such intra-Kurdish bloodletting in the 21st century. While relations with the PKK were not good after 2003, KRG leaders sought to lay down red lines regarding what others can ask of them regarding fellow Kurds. At the same time that they sought to demonstrate to neighboring states that an autonomous or independent South Kurdistan would not intervene in other countries' "Kurdish problems," KRG leaders insisted that the days of making Kurds kill Kurds were finished.

Therefore, the KRG's strategy of convincing neighboring states that they can live with an autonomous or independent government in Hawler may come as a betrayal to the Kurds of the PKK. Already before the latest conflict, KRG leaders had severely constrainted Rojava Kurds' freedom to cross their mutual border or bring in goods from South Kurdistan. This policy was put in place at least partly to mollify Ankara. At a time when Kurdish areas in Rojava such as Kobani were under an IS siege, no KRG forces came to their brethren's aid there lest Ankara and Damascus be provoked. In order to appease Tehran, Iranian Kurdish groups based in South Kurdistan, such as the Kurdistan Democratic Party of Iran and Komalah, were forbidden to launch attacks against Iran. When the PKK-linked Free Life Party of Kurdistan (PJAK) conducted an offensive against Iranian government forces a few years ago, KRG leaders worked hard to secure a ceasefire.

The KRG's strategy since 2003 thus clearly rested on an attempt to convince the international community and especially neighboring states that they could live with an independent South Kurdistan. Because Kurdistan is landlocked, it absolutely must have to friendliness and cooperation of at least one neighboring state in order to break its dependence on Baghdad. If leaders in Hawler are unable to convince neighboring states that they do not harbor any "pan-Kurdish" irredentist goals, they will fail to secure such friendliness and cooperation. As a result, it appears uncertain whether or not South Kurdistan will in the near future fully reciprocate for the great risks and sacrifices that the the fithers from other parts of Kurdistan took in its defense.