Al-Qaeda (also commonly spelled al-Qaida or al-Qa'ida) is said to be an Islamist organization founded in the late 1980s by the son of a Saudi Arabian business family with close connections to the American Bush family. It is identified as Sunni (not Shia) and is said to be a network of alienated male Muslims who hate the West and wish to either destroy (via Jihad) or convert it. There are also those who claim that al-Queda is an invention of the CIA, and that the name merely stands for "the base" – a database of Islamic activists reportedly maintained by the CIA.
Al-Qaeda is said to have been behind the 9/11 airplane attacks that led to the collapse of New York's World Trade Center towers, after which the United States launched first the Afghanistan war and then the Iraq war. There is some question, however, as to whether al-Qaeda has ever formally claimed responsibility for the attacks and whether reliable evidence exists as to whether bin Laden himself has ever done so.
Some argue that al-Qaeda, to the degree it still exists, seeks to create a new Islamic caliphate, perhaps located in Pakistan or Afghanistan. While bin Laden was said to have led the initial group, it is not so clear who might lead it now or even whether bin Laden had been still alive when the US government claimed a team of Navy Seals killed him, in May of 2011. There is much speculation that bin Laden died in the early or mid-2000s, either from assassination or illness. His funeral in December 2001 was reported in Egyptian and Pakistani newspapers.
From an economic point of view, the idea that bin Laden was leading a band of stateless terrorists from Afghanistan to Pakistan to Iraq to Yemen, etc. is not particularly feasible. And in fact, if one peers behind the curtain, the allegations of al-Qaeda attacks often seem to fade away when it turns out that the stateless terrorist who carried out such attacks is actually a Pashtun, an Iranian, Pakistani, etc.
In fact, those who criticize the concept of al-Qaeda as an extant, worldwide fighting force point out that the purported bin Laden sleeper cells in America and Britain never materialized. His fabulous Afghan mountain fortresses never turned up. Much evidence suggests his broadcasts were likely faked (particularly likely since he was probably already dead). The "fighters" that were filmed with him prior to 9/11 – according to the BBC – were hired day-to-day and told to bring their weapons. There is little doubt that Bin Laden and others around him were at one point CIA assets, trained and aimed at the Russians who were then invading Afghanistan.
Those who subscribe to free-market economic theory might well conclude that free-floating, endless, nonstate (stateless) terrorism, unfunded and illogically destructive, is simply not economically feasible, let alone sensible. There must always be the backing of some sort of state or a significant number of citizens within a state when it comes to terrorism. Thus, if al-Qaeda does exist, it should at this point be affiliated in some sense with one or more of the anti-Western states that exist in the Middle East or Africa.