The White House this week marked the fifth anniversary of the death of al-Qaida leader Osama bin Laden by posting a piece by National Counterterrorism Center Director Nick Rasmussen on the White House website.
It was Rasmussen's recollection of being in the White House Situation Room when U.S. forces took bin Laden down.
"Five years ago, I watched in the Situation Room along with President Obama, Vice President Biden, and members of the president's national security team to see if U.S. Special Operations Forces could deliver the justice that every American had been waiting for for a decade," Rasmussen wrote.
But killing bin Laden did not kill the radical Islamist ideology he embraced. Nor did killing Abu Musab Zarqawi before him.
Indeed, the strategic plan that bin Laden's top lieutenant, Ayman al-Zawahiri, outlined for Zarqawi in 2005 is at this moment being advanced by the late Zarqawi's terrorist group, which is now divorced from al-Qaida and calls itself the Islamic State.
In October 2005, the office of the director of national intelligence released a letter Zawahiri sent to Zarqawi in July of that year. An English translation of this letter is currently available on the website of the Combating Terrorism Center at West Point.
Zawahiri told Zarqawi that he was "blessed" to be at the struggle's main front.
"What I mean is that God has blessed you and your brothers while many of the Muslim mujahideen have longed for that blessing, and that is Jihad in the heart of the Islamic world," said Zawahiri.
He pointed to four "stages" he envisioned in that struggle.
"The first stage: Expel the Americans from Iraq," Zawahiri wrote.
"The second stage: Establish an Islamic authority or amirate," he said, "then develop it and support it until it achieves the level of a caliphate -- over as much territory as you can to spread its power in Iraq, i.e., in Sunni areas, is in order to fill the void stemming from the departure of the Americans, immediately upon their exit and before un-Islamic forces attempt to fill this void, whether those whom the Americans will leave behind them, or those among the un-Islamic forces who will try to jump at taking power."
"The third stage: Extend the jihad wave to the secular countries neighboring Iraq," said Zawahiri.
"The fourth stage: It may coincide with what came before: the clash with Israel, because Israel was established only to challenge any new Islamic entity," he said.
What has happened since Zawahiri sent Zarqawi this letter?
Almost 10 years ago, in June 2006, U.S. forces killed Zarqawi in Iraq. Five years after that, in May 2011, U.S. forces killed bin Laden in Pakistan.
For more than six years after Zawahiri sent his July 2005 letter to Zarqawi, the U.S. maintained troops in Iraq. According to the Congressional Research Service, those troops peaked at 170,300 in November 2007, more than a year after Zarqawi's death.
In December 2011, President Obama removed all remaining U.S. forces from Iraq.
"But we're leaving behind a sovereign, stable and self-reliant Iraq, with a representative government that was elected by its people," Obama said then.
In 2014, the Islamic State (now led by Abu Bakr al-Baghdadi) and Zawahiri's al-Qaida parted ways.
And the Islamic State now controls territory in both Syria and Iraq, where it has declared a "caliphate" and where it is committing genocide against Christians and other religious minorities.
President Obama has sent more than 4,000 U.S. troops back into Iraq and last week the administration announced he was adding 250 U.S. troops to the 50 already in Syria.
But, as recent history has demonstrated, a U.S. ground war in the Middle East will not eradicate the threat posed by radical Islamist terrorist groups, such as the Islamic State.
Instead, America needs to do everything necessary to keep Islamist terrorists from entering this country while supporting the Arab governments that understand the same threat.