Here's an unusual way to instill fear into the heart of your enemy: promise an "unbelievably small" war.

At a joint press conference this morning with British Foreign Secretary William Hague in London, Secretary of State John Kerry did just that when describing the military strike the United States is considering against Syria.

"We will be able to hold Bashar Assad accountable without engaging in troops on the ground, or any other prolonged kind of effort, in a very limited, very targeted, very short-term effort," Kerry said. He further emphasized that it would be an "unbelievably small, limited kind of effort."

The comments are part of an aggressive effort by the Obama administration to convince the American public and members of Congress that any U.S. military action against Syria would not evolve into a full-fledged war, as in Iraq or Afghanistan.

"We're not talking about war. We're not going to war," Kerry said. "We will not have people at risk in that way."

While American boots on the ground have been ruled out, ABC News has learned that the Pentagon is preparing a significantly expanded air campaign over Syria to include long-range bombers flying from the U.S., in addition to sea-launched Tomahawk missiles.

A senior national security official told ABC News last week that a U.S. military strike on Syria will do more damage to the forces of Syrian President Bashar al-Assad in 48 hours than Syrian rebels have done in two years of civil war.

Assad said today the U.S. "should expect everything" in response to a U.S. strike on his country.

"What do wars give America? Nothing. No political gain, no economic gain. No reputation. This war is against the interest of the United States," Assad told CBS News.

"America will be on same side as al-Qaeda," he said, referring to terrorist elements that are part of the rebel forces challenging his regime. "We expected this administration to be different from Bush's. Instead it is the same doctrine, different accessories."