Iraq's Kurdish region faces serious geographic challenges when it comes to defense. The territory is roughly crescent-shaped. The interior of the crescent, which faces Iraq's disputed territories, starts as flat, open desert and steadily elevates into hills, ultimately transitioning to mountains that anchor the borders with Turkey and Iran. Much of the region's critical energy infrastructure, both within the Kurdistan Regional Government proper and in the disputed regions surrounding Kirkuk, lies near areas of Iraqi territory now claimed by Islamic State militants and in open desert. Critical cities such as Dohuk, Arbil and Kirkuk are also nestled either within or close to the disputed territories on the crescent's interior border.
Any advance by the Islamic State into peshmerga-controlled territory immediately puts the militants dangerously close to these strategic areas because of the lack of geographic depth in this highly contested borderland. Major urban centers — including the regional capital, Arbil, and Sulaimaniyah — and the region's energy infrastructure already have a more robust Kurdish peshmerga defensive presence. But Islamic State militants will continue to launch opportunistic strikes along the Kurdistan Regional Government's long southern border, leveraging their mobility to launch surprise attacks where possible against Kurdish forces along the border.
This puts the defending peshmerga at a disadvantage. They have to protect an arcing border that stretches for more than 1,000 kilometers (about 620 miles), forcing the peshmerga to travel farther to defend their positions while the Islamic State enjoys interior lines of movement. Additionally, the open land of the desert plays to the Islamic State's strength: mobility. The militants can use their fast-traveling technicals — pickup trucks outfitted with heavy weaponry — and mass quickly on any weak points along the defensive perimeter. This problem is exacerbated for the peshmerga because they are defending recently gained territory and are thus readjusting their entire security presence to consolidate places in Kirkuk and Diyala provinces, which were under an immediate threat from the Islamic State earlier in the conflict. With the peshmerga overstretched, the Islamic State took advantage of these security gaps and pushed in unexpected directions from the Mosul area and areas farther west.
Turkey, Iran and the United States each have a fundamental interest in preventing a large-scale assault by Islamic State militants on Iraq's federal Kurdish region. International support for the Kurds, somewhat in conjunction with Baghdad, is likely to continue focusing on preventing a wholesale collapse of the Kurdish region or the loss of large swaths of Kurdish territory to Islamic State militants. Short of this threat, which Stratfor still considers to be unlikely at this time, additional outside assistance to Kurdish forces is likely to be limited to airdrops of humanitarian aid and targeted airstrikes against Islamic State targets.
The Americans and Turks are also likely to consider hitting Islamic State artillery positions. It will be far harder for the Islamic State to attack well-entrenched troops if it loses its artillery. There is also ongoing intelligence sharing and coordination, but support will consist of the minimum necessary to enable the Kurds to protect their core territory, and the United States and Turkey are unlikely to commit forces for combat. However, this support could expand into the realm of financial support, ammunition and logistics and combat-enabling hardware, such as night vision equipment and body armor.
Both Turkey and Iran are reluctant to give Kurdish forces heavy arms and supplies given their respective concerns regarding domestic Kurdish separatist groups. The United States is also keen to avoid alienating Iraq's Sunni and Shiite Arab groups, which are currently locked in difficult political negotiations in Baghdad. Ankara, Tehran and Washington will provide minor assistance geared toward preventing the establishment of an Islamic State launching ground in the Kurdish region for strikes against Turkish, Iranian or energy targets, but there is a clear consensus against providing enough material help to support future Kurdish independence claims or embolden the Kurds to engage Arab Iraqi competitors with more robust conventional military capabilities.
Peshmerga forces are scrambling again to reorient and establish blocking positions in critical areas. When able to concentrate forces, and with foreign support and assurances, the peshmerga will have the advantage. Moreover, deeper into Kurdish territory the terrain becomes more rugged and favors defensive positions. However, the Islamic State still has its mobility, shorter lines and a long border to take advantage of, and many oil blocks are close enough to be threatened by potential raids.