Yes, Bush caused this...
What are the Islamic State's origins?
The group that calls itself the Islamic State can trace its lineage to the aftermath of the U.S. invasion of Iraq, in 2003. The Jordanian militant Abu Musab al-Zarqawi aligned his Jama’at al-Tawhidw’al-Jihad with al-Qaeda, making it al-Qaeda in Iraq (AQI).
Zarqawi’s organization
took aim at U.S. forces (PDF), their international allies, and local collaborators. It sought to draw the United States into a sectarian civil war by attacking Shias and their holy sites, including the Imam al-Askari shrine, in 2006, and provoking them to retaliate against Sunnis.
Zarqawi was killed in a U.S. airstrike that year. The emergence of the U.S.-backed Awakening, or Sons of Iraq, coalitions further weakened AQI as Sunni tribesmen reconciled with Prime Minister Nouri al-Maliki’s Shia-led government. Zarqawi’s successors rebranded AQI as the Islamic State of Iraq and later, the Islamic State of Iraq and al-Sham (ISIS), referring to a territory that roughly corresponds with the Levant, reflecting broadened ambitions as the 2011 uprising in Syria created opportunities for AQI to expand. The group is known to its followers as
il-Dawla (“the State”) and its Arabic-speaking detractors as
Daesh, the Arabic equivalent of the acronym ISIS.
The Islamic State’s current leader, the self-proclaimed caliph Abu Bakr al-Baghdadi, spent time in
U.S.-run prisons in Iraq. Cells organized in them, along with
remnants of Saddam Hussein’s ousted secular-nationalist Ba’ath party, make up some of the Islamic State’s ranks.
http://www.cfr.org/iraq/islamic-state/p14811