As the Islamic State group continues its advance, Kurdish forces loyal to the Kurdish Regional Government in Iraq's north are struggling to withstand the terrorist threat. The Kurds are pressing Washington for more arms and support. To this day, Iraqi Kurdistan, a region made up of three provinces in Iraq's north that is governed autonomously, remains one of the parts of the Middle East most well-disposed to the United States. But those ties are once more being put to the test.

With the Islamic State now pushing against Iraqi Kurdistan's borders, an old question has gained renewed attention: How much leeway should the U.S. give to the Kurds? The Kurds have made no secret of their longstanding desire for a more complete independence from Iraq's central government. But, so far, the U.S. has sought a strong and united federal Iraqi government. Yet the sectarian politics of the leadership in Baghdad, which is mostly Shiite, is partly to blame for the chaos gripping the region. Now it may be in the U.S.'s interest to more directly back the Kurds.

For the past century, the U.S. has at times entertained and, in other moments, ignored the Kurdish question. Iraq itself is the product of three old Ottoman vilayets, or provinces, that were subsequently claimed by British mandate after the end of World War I and the fall of the Ottoman Empire. At the time, President Woodrow Wilson supported the idea of autonomy for non-Turks in the Ottoman Empire. But the Kurds were to be disappointed: denied their own self-determination, their lands were split among Iran, Turkey and Iraq. The latter's ethnic and religious divisions are highlighted in the map below:

Here are some of the key events that led to today's situation:

1963 - Then-Iraqi leader Abdel Karim Kassem is deposed in a coup that is reportedly supported by the U.S. government. Subsequently, Washington advises the Kurdish Iraqis to support the newly installed central government led by the Iraqi Ba'ath Party, a secular Arab nationalist political movement.

1970 - Following that encouragement, an agreement is reached between the Kurdish Democratic Party and the central government, which promises more autonomy to the Kurds. The deal is negotiated with a politician who will later become known for his brutal repression of the Kurds: Saddam Hussein, at that time vice president of Iraq.

1972/1973 -  Iraq's Ba'ath party has become a threat in the eyes of the U.S. government. President Nixon and Iran's shah begin to fund the Kurdish pesh merga guerrillas and support their claims for autonomy. In 1972, Saddam Hussein had signed a "Friendship and Cooperation" treaty with the USSR.

1975 - After the surprising Algiers Agreement between Iran and Iraq is reached, the U.S. stops its support for the Kurdish rebels which causes the fragmentation of the opposition and an increased vulnerability to Saddam Hussein's renewed attacks. While he exacts brutal revenge on the Kurds (including a catastrophic chemical weapons attack in 1988 that kills thousands) the U.S. breaks off all official relations to the opposition it previously backed.

1990 - Iraq occupies Kuwait, prompting the First Gulf War, which ends the alienation between the U.S. and the Kurds that had lasted for more than a decade. Iraq is defeated in Kuwait, but a subsequent uprising of Shiite Iraqis and Kurds (Saddam Hussein's Ba'ath party is primarily seen as Sunni-supported) fails to gain U.S. support. The uprising is unsuccessful but Kurdish areas receive greater autonomy in 1991 when a 'safe haven' is set up by the UN. A U.S.-backed opposition group called Iraqi National Congress will be based in Kurdistan in the following years. However, inner-Kurdish cleavages emerge.

1996 - As a result of these rivalries, the Kurdish Democratic Party (KDP)  attacks the Iraqi National Congress in Erbil with the help of Saddam's army. Many rebel fighters are captured and executed by the attackers after the U.S. refuses to provide air support.

2003 - The U.S. invasion of Iraq results in cooperation between the two main Kurdish adversaries, the KDP and the PUK.  Kurdish forces fight alongside U.S. troops against Saddam's government.

2005 - A regional Kurdish parliament is formed. Soon afterwards, oil discoveries lead to a fear within Iraq's central government in Baghdad that the Kurdish autonomous region could try to secede. Furthermore, tensions between Turkey and Kurdish rebels in northern Iraq arise and provoke clashes. Turkey's tough measures against its own Kurdish population extend over the border into Iraq.

Since invading Iraq, the U.S. has continuously supported the country's unity and has recently been particularly worried about an oil pipeline that connects Kurdish areas and Turkey because it could make the Kurds financially independent from Baghdad. But the sudden success of the Islamic State might be changing the calculus. The question posed now is: Will the U.S. allow terrorists to brutally conquer the area with unforeseeable consequences -- or will it support the Kurds in a fight that might lead to their independence?