WASHINGTON —

It has been over a year and a half since Osama bin Laden was killed in Abbottabad, Pakistan, but now it seems as if al-Qaida is everywhere: from Algeria to Somalia, from Mali to Yemen, from Pakistan to Iraq. In July 2011, arriving in Afghanistan on his first trip as U.S. defense secretary, Leon Panetta said, “We’re within reach of strategically defeating al-Qaida.” But on Jan. 16, Panetta seemed to express a good deal less optimism, making clear that the Algerian hostage crisis currently unfolding was “an al-Qaida operation.” So has al-Qaida really become this web of linked groups around the world pursuing a common jihad against the West? And what is the relationship between the al-Qaida core and its affiliate organizations?

These are important questions; the debate about whether the United States should join the French and step up involvement against jihadi groups in Mali centers on these complicated ties.

For while al-Qaida leader Ayman al-Zawahiri and his lieutenants in the Afghanistan-Pakistan area consume much of our thinking on al Qaida, the United States is also fighting al Qaida affiliates like al-Qaida in Iraq (AQI), the Yemen-based al-Qaida in the Arabian Peninsula (AQAP), and al-Shabab in Somalia, which is also linked to al-Qaida.

In 2012, the United States conducted more drone strikes on AQAP targets than it did against al-Qaida core targets in Pakistan. In Mali, U.S. concern is heightened by reports that some among the wide range of local jihadi groups like Ansar Dine have ties to al-Qaida in the Islamic Maghreb (AQIM). If groups in Mali and other local fighters are best thought of as part of al-Qaida, then an aggressive effort is warranted.

But if these groups, however brutal — and despite the allegiances to the mother ship they claim — are really only fighting to advance local or regional ambitions, then the case for direct U.S. involvement is weak. The reality is that affiliation does advance al-Qaida’s agenda, but the relationship is often frayed and the whole is frequently far less than the sum of its parts.

A vanguard to follow

Al-Qaida has always sought to be a vanguard that would lead the jihadi struggle against the United States. Abdullah Azzam, one of the most influential jihadi thinkers and a companion of bin Laden, wrote, “Every principle needs a vanguard to carry it forward” and that this vanguard is a “solid base” — a phrase from which al-Qaida draws its very name.

At the same time, al-Qaida sought to support and unify local Muslim groups as they warred against apostate governments such as the House of Saud in Saudi Arabia and Hosni Mubarak’s Egypt. Convincing local groups to fight under the al-Qaida banner seems to neatly combine these goals, demonstrating that the mother organization — now under Zawahiri — remains in charge, while advancing the local and regional agendas that the core supports.

More practically, in the past, the al-Qaida core has offered affiliates money and safe haven. In Afghanistan, and to a lesser degree in Pakistan, jihadists from affiliated groups came to train and learn and proved far more formidable when they returned to their home war zones.

They also returned with a more global agenda, advancing the core’s mission of shaping the jihadi movement. It also gave the core a new zone of operational access to conduct terrorist attacks in other places.

Perhaps most importantly, the core al-Qaida managed to change the nature of the affiliates’ attacks, so that in addition to continuing to strike at local regime forces, they also select targets more in keeping with the core’s anti-Western goals. AQIM’s attack last week on Western tourists and foreign oil workers in Algeria mimics the change in strategy. AQAP has taken this one step further and gone after the United States outside its region, twice launching sophisticated attacks on U.S. civil aviation.

Yet affiliation is risky for all concerned. Some groups come to al-Qaida as damaged goods: AQIM, for example, largely lost its struggle in Algeria before it came under the core banner. AQI committed a series of brutal atrocities in Iraq despite the chastisement of al-Qaida leaders and in so doing provoked a firestorm of criticism from previously sympathetic clerics in the Muslim world.

In documents captured in the Abbottabad raid, one jihadist had warned bin Laden, “The problem is that al-Qaida has become a broad field; each can enter.” The implication: By absorbing these far-flung franchises under its banner, the core could not disassociate itself from the actions of far-flung affiliates.

Perhaps unsurprisingly, al-Qaida leaders explored whether they could cut ties to some of these groups.

For the local groups, going global brings a host of downsides, particularly the wrath of the United States and other strong powers. Journalist Jason Burke quotes the jihadi strategist Abu Musab al-Suri who lamented the 9/11 attacks cast “jihadists into a fiery furnace. … A hellfire which consumed most of their leaders, fighters and bases.”

Similarly, because the core is less in tune with conditions and realities on the ground in the countries in which its far-off satellites operate, mistakes at the local level are more likely to occur when the core is calling the shots.

And when al-Qaida sends its own operatives and other nonlocals to join an affiliate, these foreign fighters may alienate locals through their personal behavior or attempts to alter local traditions. In Iraq, Burke reports that one local jihadist shot a foreign fighter who had said that he could not pray at the grave of his ancestors, because doing so would be considered a form of idolatry.

No simple solutions

Ultimately, there are no simple choices when confronting al-Qaida affiliates. On the one hand, ignoring groups until they become affiliates, or ignoring affiliates until they strike at U.S. targets, risks leaving intelligence and security officials — not to mention Barack Obama’s administration — in a defensive and reactive mode and vulnerable to a surprise attack.

On the other hand, too aggressive an approach can create a self-fulfilling prophecy, strengthening bonds between al-Qaida and other jihadi groups by validating the collective narrative and leading groups to cooperate for self-defense and organizational advancement. But the United States needs to pick its battles. It is vital to distinguish between those groups that are full-fledged affiliates and those groups that have just limited interaction with al-Qaida.

In Mali, the verdict is still out. There are a hodgepodge of local groups with shifting alliances and unclear links to Zawahiri and the core. They pose a danger to Mali and its neighbors — and to Americans in this turbulent zone — but for now they lack the capacity and perhaps the interest in striking the U.S. homeland. It is sensible for U.S. officials to worry that this could change over time.