U.S. airstrikes against ISIS target oil tanker trucks

A CBS News poll just out on Monday night finds that 36 percent of Americans approve of President Obama's handling of terrorism. That is down from 72 percent, right after U.S. forces killed Osama Bin Laden in 2011.

Only 23 percent of Americans believe the president has a clear plan for dealing with ISIS. His strategy includes air strikes in Iraq and Syria, and the latest targets include oil.

Two airstrikes, the most recent over the weekend, have destroyed almost 500 tanker trucks ISIS uses to smuggle oil and sell it on the black market.

By one estimate, these attacks have destroyed roughly half the trucks ISIS uses to bring in $1 million a day in revenues.

Until now, the U.S. has not gone after the tankers for fear of killing the civilian drivers.

In these strikes, U.S. planes first dropped leaflets warning the drivers and then conducted staffing runs to scare them away.

The U.S. has also loosened rules on civilian casualties. Previously, a strike would be called off if any civilians were spotted in the area. For these, more than five civilians had to be in the target area before the strike would be called off.

The French have now begun launching strikes against ISIS from an aircraft carrier in the Eastern Mediterranean. And the Russians have fired a total of 42 cruise missiles against ISIS targets in Syria.

Cutting off oil revenues will degrade ISIS, but the quickest way to defeat it on the battlefield is to seize its capital of Raqaa in Syria.

The red line on this Pentagon map shows how close U.S. backed fighters are to Raqaa -- just 30 miles to north and 100 miles to the east.

U.S. officials say the fighters to the north don't have enough combat power to take Raqaa and the fighters to the east must first push south to seize a key road junction before advancing on Raqaa. The fighters will be assisted by 50 American Green Berets, but they are not expected to get there until next month.

Think of it as a race against time, can U.S. backed fighters seize Raqaa before ISIS can launch another terrorist attack against the West?