WASHINGTON, AP -In a letter to his top deputy in Iraq, al-Qaeda”s No. 2 leader said the United States &#34ran and left their agents&#34 in Vietnam and the jihadists must have a plan ready to fill the void if the Americans suddenly leave Iraq.

&#34Things may develop faster than we imagine,&#34 Ayman al-Zawahri wrote in a letter to his top deputy in Iraq, Abu Musab al-Zarqawi. &#34The aftermath of the collapse of American power in Vietnam — and how they ran and left their agents — is noteworthy. … We must be ready starting now.&#34

Senior U.S. military commanders have said that Iraqi security forces are improving significantly and some U.S. forces could return home early next year. Yet skeptics have raised concerns about whether such statements simply let the insurgency know how long they must wait for the U.S. to leave.

In a letter taking up 13 typed pages in its English translation, al-Zawahri also recommended a four-stage expansion of the war that would take the fighting to neighboring Muslim countries.

&#34It has always been my belief that the victory of Islam will never take place until a Muslim state is established … in the heart of the Islamic world,&#34 al-Zawahri wrote.

The letter laid out his long-term plan: expel the Americans from Iraq, establish an Islamic authority and take the war to Iraq”s secular neighbors, including Lebanon, Jordan and Syria.

The final stage, al-Zawahri wrote, would be a clash with Israel, which he said was established to challenge &#34any new Islamic entity.&#34

The letter is dated July 9, and was acquired during U.S. operations in Iraq. It was written in Arabic and translated by the U.S. government. The Pentagon briefed reporters last week on portions of the document, but the full text was not available until Tuesday.

In a statement, the National Intelligence Director”s office said the letter &#34has not been edited in any way&#34 and its contents were released only after it was clear no military or intelligence operations would be compromised.

House Intelligence Chairman Peter Hoekstra, R-Mich., said his committee is reviewing the letter, but he cautioned &#34against reading too much into a single source of intelligence.&#34

In his letter, al-Zawahri, a Sunni, devoted significant attention to al-Zarqawi”s attempts to start a civil war with the rival Muslim Shiite sect, the majority that now dominates the new Iraqi government. Ultimately, al-Zawahri concluded that violence, particularly against Shiite mosques, only raises questions among Muslims.

&#34This matter won”t be acceptable to the Muslim populace however much you have tried to explain it, and aversion to this will continue,&#34 he wrote.

Al-Zawahri was also critical of the Taliban, which was toppled in the 2001 U.S.-led invasion of Afghanistan, because, he said, they did not have the representation of the Afghan people. He said students of the Taliban retreated to their tribes.

&#34Even the devout ones took the stance of spectator,&#34 al-Zawahri wrote.

Contrasting that, he saw fearlessness in battles waged in the Iraqi cities of Fallujah, Ramadi and Al Qaim.

At times, the letter got personal. Al-Zawahri said he tasted the bitterness of America”s brutality, noting that his &#34favorite wife”s chest was crushed by a concrete ceiling&#34 during an apparent U.S. attack. His daughter died of a cerebral hemorrhage.

To this day, he wrote, he did not know the location of their graves.

The letter then switches to the court of public opinion.

&#34More than half of this battle is taking place in the battlefield of the media,&#34 he wrote. &#34We are in a media battle in a race for the hearts and minds of our umma,&#34 or community of Muslims, he wrote.

The line is an apparent reference to a phrase — &#34hearts and minds&#34 — often used by President Bush.