JEFFREY BROWN: And we return now to Syria.
In an interview published today, President Bashar al-Assad said that only direct foreign military intervention can threaten his government. He added that he believed that would never happen. While direct intervention remains off the table for the United States, there has been a change to strengthen Assad's enemies on the battlefield.
Margaret Warner reports on those efforts and moves to back rebels in past conflicts.
MARGARET WARNER: Three weeks ago, the Obama administration, in a policy shift, announced it would provide what it called dramatically increased assistance to some elements of the Syrian rebels.
Since then, White House officials have offered few details on what the military aid would look like.
Deputy National Security Adviser Ben Rhodes spoke publicly about it on June 14.
BEN RHODES, U.S. deputy national security adviser: I can't give you a specific timeline or an itemized list of what that assistance is and when it will get there.
And what we want to do with our assistance is strengthen their effectiveness, so that they have better capabilities as they are pursuing their efforts within Syria.
MARGARET WARNER: The decision came after U.S. intelligence determined that -- quote -- "The Assad regime has used chemical weapons on a small scale against the opposition multiple times in the last year."
That crossed a red line set by President Obama earlier. The move also followed the fall of the strategic rebel-held town of Qusayr near the Lebanese border, seen as a sign that President Bashar al-Assad's forces, backed by Hezbollah fighters from Lebanon, were regaining momentum.
Early reports indicated that the U.S. assistance would be limited to small arms and ammunition. That drew criticism from Arizona Senator John McCain.
SEN. JOHN MCCAIN, R-Ariz.: The Free Syrian Army need weapons and heavy weapons to counter tanks and aircraft. They need a no-fly zone, and Bashar Assad's air assets have to be taken out and neutralized.
MARGARET WARNER: But the administration is concerned that heavy weapons intended for the Free Syrian Army rebel force could end up with more radical jihadi rebels, like those of the al-Qaida-linked Al-Nusra Front.
This is not the first time the U.S. has provided such aid. For example, during the last decade of the Cold War, in the 1980s, the U.S. furnished arms and training to the Nicaraguan Contras, as well as to the mujahideen fighting the Soviet occupation of Afghanistan.