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News about the United States' drone and air strikes against Al Qaeda tend to focus on incidents that take place in Pakistan and Afghanistan. But over the past 10 years, Yemen has become a major front for the "war on terror" — largely because some of the major Al Qaeda attacks originated there — e.g., the 2000 USS Cole attack and the 2008 attack on the U.S. embassy.

PBS Frontline has created an interactive map, America's War in Yemen, that shows the locations and provides the details of "71 known U.S. drone, missile or other air strikes carried out since 2002, and the blue dots show 19 major terror plots against Western targets believed to be directed by Al Qaeda or Al Qaeda in Yemen since 2000," with the red dots indicating U.S. attacks and the blue dots indicating Al Qaeda attacks.

The visual story is striking: The blue dots indicating Al Qaeda attacks are almost all clustered around Sana'a, the capital; and the red dots are spread all over the country. Click on each dot, and the details of the attack pop up — the date, the number of people killed and, where possible to verify, their names. Occasionally interesting additional information is included, as in the case of the September 30, 2011 drone strike that killed Samir Khan, a U.S. citizen. The pop up reminds the reader: "Awlaki is the first U.S. citizen known to have been deliberately killed by the CIA in a drone strike. His killing ignited a legal debate over whether the U.S. can target its own citizens in such an attack."

But why are the U.S. drone strikes spread out all over Yemen, while the Al Qaeda attacks are clustered in a specific area? The map begs the question, but does not provide the answer. Al Qaeda's Yemen branch is located in the south of the country, but there are many red dots indicating U.S. attacks spread over the north and north east. PBS Frontline digital producer Azmat Khan points out that whereas the anti-terror operations in Pakistan involve drone strikes in remote, sparsely populated tribal areas, the operations in Yemen are carried out by both the CIA, which uses drones, and the Joint Special Operations Command (JSOC), which employs air strikes.

Clicking on the dots to read the information also shows the escalation in the war, year on year.

PBS Frontline's map of America's war in Yemen follows a 30-minute documentary on Al Qaeda's presence in that country and a fascinating round table discussion with various U.S. diplomats and analysts who know the country well.

Corrections: This map was originally identified as a production of NPR's. It is in fact a PBS Frontline production. Similarly, Azmat Khan is a digital producer for PBS frontline — and not a producer for NPR, as previously stated in the article. Ms. Khan adds the following clarifications:

Some Al Qaeda attacks are clustered in areas like Sanaa because they were attacks on foreign embassies there. Of course, these embassies wouldn't be the target of drone strikes. Additionally, droning a densely populated capital isn't feasible.

Al Qaeda's operations are not restricted only in the south, where some Al Qaeda-affiliated groups seized territory last year.

America's targeted killing program in Yemen is comprised of both air and drone strikes, carried out by both the CIA and JSOC. It is often unclear which strikes are carried out by which agency.