The U.S. military will expand its air campaign against the Islamic State of Iraq and Syria militant group, CBS News has learned.

The expanded air campaign will not just consist of strikes in support of Iraqi forces trying to retake lost territory, CBS News national security correspondent David Martin reports. Independent of that there will also be strikes to "degrade" the capabilities of ISIS, also known as the Islamic State of Iraq and the Levant, or ISIL -- in other words, any other ISIS units that can be hit.

Martin reports that the campaign will expand gradually and that a long night of bombing should not be expected Wednesday night.

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As for Syria, there will be strikes against ISIS in Syria "eventually," a source told CBS News, as targets are identified. There is still more work to do to develop targets there.

There will be an increase in the number of American military personnel on the ground in Iraq. But the size of the increase is not clear.

The U.S. has conducted 154 airstrikes in support of Iraqi troops and Kurdish peshmerga forces battling ISIS since Aug. 8. The Pentagon released a statement Wednesday saying it had damaged or destroyed 212 ISIS "targets" in total. Military officials said they have also conducted two major humanitarian operations and assisted in a major resupply of Kurdish forces.

It began attacking ISIS near the Haditha Dam last weekend, citing it as a strategic target that could not be allowed to fall into the extremists' hands.

On Tuesday, the U.S. military said it launched five more airstrikes in support of Iraqi government troops and Sunni tribesmen protecting the Haditha Dam.

U.S. Central Command said that a combination of U.S. attack, fighter and drone aircraft destroyed or damaged eight armed vehicles, two of which were transporting anti-aircraft artillery near the dam. It said six other vehicles also were struck.

The attacks were carried out overnight Monday into Tuesday morning.

On Wednesday evening, President Obama will deliver a primetime public address about ISIS and will likely discuss the expansion of the U.S. military campaign against it.

Some critics, including even Hillary Clinton, Mr. Obama's former secretary of state, have suggested that if the Obama administration had more aggressively armed the moderate rebels in Syria last year, ISIS would have less of a foothold in the region.

"The failure to help build up a credible fighting force of the people who were the originators of the protests against Assad -- there were Islamists, there were secularists, there was everything in the middle -- the failure to do that left a big vacuum, which the jihadists have now filled," Clinton recently said.

Of course, with hindsight, the potential threat of ISIS may be more evident, and it seems to be growing more evident to Washington on a daily basis. Even Sen. Rand Paul, R-Kentucky, who just last month slammed Clinton for suggesting the U.S. take a more aggressive posture in Syria, now supports airstrikes in both Iraq and Syria.

In addition to rallying U.S. public support for the campaign, Secretary of State John Kerry traveled to the Mideast this week to try to build a coalition against ISIS.

Kerry landed in Baghdad Wednesday to show support for new Iraqi Prime Minister Haider al Abadi, whose government is a cornerstone in the Obama administration's plan to deal with ISIS.

Mr. Obama dispatched Kerry to gin up pledges of support from Arab leaders in the region -- many of whom are skeptical of the U.S. commitment to the use of force and accuse the U.S. of being slow to act.

Until now, an expansion of U.S. military and financial aid had been on hold until a new central government was formed in Baghdad. Mr. Obama made that a precondition since U.S. policymakers believe the alienation of the Sunni minority by former Prime Minister Nouri al-Maliki broadened the appeal of ISIS' anti-government attacks.

With a new Iraqi prime minister now in office, the U.S. can push his government to the forefront of the fight against ISIS.