Fate of ISIS leader still unknown

Iraqi forces claimed a big win in their fight with the Islamic terrorist group known as the Islamic State of Iraq and Syria (ISIS) on Tuesday, retaking the northern town of Beiji, home to Iraq's largest oil refinery.

Since the weekend, there have been conflicting reports on the fate of the leader of ISIS.

It's been more than 72 hours since Abu Bakr al Baghdadi was reported injured in an airstrike, and still there are no hard facts to confirm or deny.

But even if the ISIS leader was hurt -- or killed -- ISIS would quickly find a successor in its battle-hardened senior ranks.

There have now been 740 American airstrikes in Iraq and Syria since early August, including at least one near Mosul last Friday that targeted a convoy of ISIS leaders.

But there's no proof al Baghdadi was among them.

The bombs have slowed the militants' speedy advance and helped Kurdish peshmerga soldiers in the north hold their ground.

In the town of Kobani, they even pushed ISIS back, but that was an exception.

In spite of the U.S. military spending an average of $8.3 million a day on this operation, ISIS hasn't given up much -- if any -- territory.

It still controls a huge wedge -- more than 10,000 square miles -- of Iraq and Syria, including major roads and border crossings.

To win that back, there will have to be competent boots on the ground. Iraqi boots, that is.

At the moment, as CBS News saw on recent visit, the Iraqi army is holding its own around Baghdad, but it has struggled to win any major offensives operations recently against better disciplined, and in some cases, better-armed ISIS units.