Abstract. New upheavals have shaken the Middle East this summer. A small but determined army of Sunni jihadists that had operated in the war-torn Syria suddenly crossed the border into Iraq and launched a large-scale military campaign. In a matter of days the invaders captured the second largest city of Iraq, Mosul, and although heavily outnumbered by the Iraqi army, put it to flight. The militants, known as ISIS (the Islamic State of Iraq and Sham, the latter word meaning Syria and Lebanon) and led by an exceedingly tough and ruthless commander Abubaqr al-Baghdadi, are descendants of the infamous terrorist international network Al-Qaeda. Actually, the ISIS members represent the third generation of Al-Qaeda militants who waged the war against the Soviet Army in Afghanistan back in 1989-s and later fought the Americans in Iraq in the wake of the U.S. invasion. Lately they joined the Syrian armed opposition that has been trying to overthrow the regime of Bashar al-Assad for about three years. Now that the military situation in Syria appears to favor the embattled president, ISIS has probably come to the conclusion that its priority is not necessarily the ousting of Assad; rather it is the creation of an Islamic state according to the name of their organization. Exactly this seems to be the rationale for their comeback into Iraq. The Sunni jihadists whose ultimate aim is to resurrect the medieval Islamic Caliphate have to confront both the Iraqi Kurds who live in a virtually semi-independent state formation and the Shia Arabs who mostly inhabit the southern part of Iraq. Yet, both communities, although probably capable of protecting North, South and the capital city, are hardly likely to reassert the government authority in the central part of the country. What is necessary is the assistance from abroad. The Shia-dominated Iraqi government of Nouri al-Maliki, in deep trouble, is looking to both Iran and the U.S. for military aid. Both Washington and Tehran, however, appear reluctant to be seen as wholeheartedly backing the Shia side if only for fear of alienating the mainstream Arab States who are of course Sunni. This is a pretty delicate situation indeed.