Palestinian fighters from the Izz el-Deen al-Qassam Brigades, the armed wing of the Hamas movement, in a Gaza tunnel in August 2014. The group is named in honor of a Palestinian preacher who railed against the British Mandate in Palestine and latter organized armed resistance. Qassam was killed along with two followers in a shootout with British police in 1935, and he became a hero of militant Palestinian nationalism after his death. Mohammed Salem/Reuters
A fighter from the self-styled Islamic State, takes part in a military parade in Syria's northern Raqqa province in June 2014. The parade was a celebration of the Syria and Iraqi-based salafi jihadi group's declaration of a "caliphate" after it captured territory in northern Iraq. Unlike Al Qaeda, which is obsessed with destroying "far enemies" like the US before seeking to impose it's version of sharia on the world, IS is focused on state building as a first step. Reuters
Al Shabab fighters conduct a military exercise in northern Mogadishu, Somalia, January 2010. The young men had recently completed training to join that they said was a global for God. 'Al Shabab' means 'The Youth' and emerged in Somalia in the middle of the last decade after Ethiopian troops overthrew another Islamist movement that was its forerunner. Farah Abdi Warsameh/AP
Members of the Libyan salafi jihadi group Ansar al-Sharia guard the gates of a main hospital to protect doctors from armed youths in Benghazi in September 2012. The group - the name means 'helpers of Islamic law' - is a major player in the current war to control Libya. Asmaa Waguih/Reuters
Militiaman from the Ansar Dine Islamic group, who said they had come from Niger and Mauritania, ride on a vehicle at Kidal in northeastern Mali in June, 2012. The rebels have engaged in typical salafi jihadi iconoclasm: After entering Timbuktu that year, they destroyed at least eight ancient mausoleums and shrines to revered Sufi preachers. Adama Diarra/Reuters
Fighters from the Islamic State in Iraq and the Levant (ISIS) shortly before destroying seized cigarettes in Raqqa, Syria, near the Iraqi border on April, 2014. ISIS, which renamed itself simply the 'Islamic State' in June, has harshly enforced bans on alcohol and cigarettes in areas it controls, with whippings and other punishments. It has also beheaded people or chopped off their hands for alleged crimes. Reuters
A Pakistan Taliban member with a rocket-propelled grenade in the Taliban stronghold of Shawal, in Pakistan's tribal Waziristan Province along the Afghanistan border in August 2010. Pakistan's lawless border regions have long provided refuge for both the Afghan and Pakistan Taliban. Ishtiaq Mahsud/AP
An unidentified speaker at a 'standing prayer' organized to honor Al Qaeda leader Osama bin Laden in Khartoum, Sudan, in May 2011. Around 1,000 people gathered to praise Bin Laden, chanting "Death to America". Reuters
British Islamists protest outside the French Embassy in London on January 2013, after French aircraft pounded Islamist militants in Mali to hold off an attempted jihadi takeover of the northern part of that country. Suzanne Plunkett/Reuters
Members of Boko Haram, a jihadi group in Nigeria that has perpetrated a string of massacres at schools and kidnapped dozens of girls earlier this year hold a press conference in Maiduguri, Borno State of Northern Nigeria in February 2013. Reuters
Salafis hold posters showing Osama bin Laden during a demonstration near the US embassy in Tunis, Tunisia, on March, 2012. Salafi Muslims follow a harsh brand of Sunni Islam that harkens back to what they imagine was an Islamic golden age 1,400 years ago. Most Sunni jihadis can be classified as salafis, but there are also many salafis who eschew violence or even challenging established powers in their countries. Amine Landoulsi/AP
The Pentagon said Arab allies assisted overnight strikes in Syria. Islamic State bases were the main target, but the US said it also struck at a separate al-Qaeda affiliate suspected of plotting terror attacks on Western targets.
Courtesy of Mass Communication Specialist 1st Class Eric Garst/U.S. Navy / Reuters
US forces, backed by Arab allies, have launched their first airstrikes against militant targets inside Syria, reportedly killing both members of the self-declared Islamic State and those of another Al Qaeda-linked group.