Americans are getting another hurried geography lesson. Before, it was Iraq. Then Afghanistan. This time, it is Yemen.

Yemen is located on the southern tip of the Arabian Peninsula, between Saudia Arabia and Oman. It is bordered by the Arabian Sea, Gulf of Aden and the Red Sea.

Just as in Iraq and Afghanistan, geography is not as important as the reason behind its newfound connection to the United States.

Home to 23.8 million people, Yemen is one of the poorest countries in the Middle East. People subsist on pennies a day, and education is practically nonexistent. On top of that, the country is in the midst of a severe water shortage.

As such, Yemen has become a breeding ground for terrorists.

The Nigerian suicide bomber who tried to bring down a U.S. jetliner over Detroit on Christmas Day trained there for more than a month.

The episode was the first major one involving Yemen since 2000, when al-Qaida bombed the U.S. Navy destroyer, the USS Cole, while it was harbored in the Yemeni port of Aden. Seventeen American sailors were killed.

Since then, the Yemeni government has moved to strengthen ties with the U.S. government as a way to bolster its counter-terrorism efforts.

This has come today to include U.S. Special Operations Forces, Green Berets and American intelligence agents. In 2009 alone, the Pentagon provided Yemen with nearly $70 million in overt military and counter-terrorism assistance.

This largely has gone unnoticed by the American public, until now.

At the same time, the Sunni-dominated Yemeni government is dealing with a separate issue, namely rebellious Shiites, who fear the government is out to destroy them. Thousands of people have died and hundreds of thousands have been displaced because of this internal strife.

The Yemeni government is fighting two wars, one against al-Qaida and one a civil war. Little wonder, then, that al-Qaida has an increased presence that is not only showing in Yemen but beyond its borders.

The Yemen-based branch of al-Qaida has claimed responsibility for training and equipping Umar Farouk Abdulmutallab, the Nigerian "trouser bomber" who had 80 grams of an explosive cleverly sewn into his underpants. Had it not been for a faulty detonator &tstr; and the heroics of passengers and crew &tstr; nearly 300 lives could have been lost in the skies above Detroit.

Now we learn the attempt may have been in retaliation for U.S. airstrikes that President Barack Obama ordered against two suspected al-Qaida bases in Yemen a week earlier.

Al-Qaida not only has a growing presence among disaffected Yemenis, its ranks have been bolstered by the addition of at least a dozen former Guantanamo inmates, including a deputy commander.

Also among them is Anwar al Awalaki, the American-born radical preacher who counseled Maj. Nidal Hassan, the U.S. soldier charged with killing 13 comrades in a shooting rampage at Food Hood, Texas, last month.

President Obama vowed an accelerated offensive against al-Qaida in Yemen, following word that al-Qaida was taking a share of the credit for the Christmas Day suicide-bombing attempt.

Of that attempt, the president said, "We will not rest until we find all who were involved and hold them accountable."

What that means, we do not yet know.

But Yemen could be considered the kind of "gathering threat" that George Bush spoke of in reference to Iraq --  the reason behind a previous geography lesson.