Coalition forces began striking selected targets against Iraqi leader Saddam Hussein, President Bush announced in a live address from the Oval Office on Wednesday night.

"On my orders, coalition forces have begun striking selected targets of military importance to undermine Saddam Hussein's ability to wage war. These are opening stages of what will be a broad and concerted campaign," Bush said.

"Our nation enters this conflict reluctantly, yet our purpose is sure. The people of the United States and our friends and allies will not live at the mercy of an outlaw regime that threatens the peace with weapons of mass murder," he said in a calm manner as he spoke directly into the camera.

Aimed at cutting off the head of the snake, the president called for the attack ahead of schedule, according to defense officials. The Pentagon had told the news media earlier in the evening not to expect an attack on Wednesday night, which is Thursday morning in Iraq.

However, military leaders in the region apparently saw some movement happening with the leadership and acted on it, senior defense officials told Fox News. One official speaking from home said that he would not be at home if he had thought the attack was coming so soon.

Intelligence sources told Fox News that the military was aiming either at Saddam, his two sons or two other key Iraqi leaders that they had intelligence on. Sources said that intelligence officials knew where Saddam was eight hours ago and maybe sooner, and they can not rule out another surgical strike again.

Several F-117 stealth fighters dropped two precision guided bombs each and as many as three dozen Tomahawk missiles were fired from ships in the Red Sea and Persian Gulf. Now that military force has begun, sources with close ties to the Defense Department say they expect at least 1,000 bombs to fall as soon as the next wave.

"Now that conflict has come, the only way to limit its duration is to apply decisive force. And I assure you, this will not be a campaign of half measures and we will accept no outcome but victory," Bush said.

The day had started typically enough for Bush, minus the formal notice he sent to Congress in which he said he had determined "further diplomatic and other peaceful means alone" would not be enough to contain the "threat posed by Iraq." Bush has contended that Saddam possesses chemical and biological weapons that he could use on his enemies or slip to terrorists.

After meeting with Pentagon officials, including Defense Secretary Donald H. Rumsfeld on Wednesday, Bush had just finished dinner Wednesday night and was in the living room of the White House residence with first lady Laura Bush when his chief of staff, Andrew Card, called. Card informed the president that intelligence officials had no information that Saddam had left Iraq.

The president said that more than 35 countries are giving crucial support "from the use of naval and air bases, to help with intelligence and logistics, to the deployment of combat units."

British forces told Reuters news service that no ground attack had been ordered yet. The Pentagon had said before that the air assault would take somewhere between 24 to 72 hours in order to blind and deafen the Iraqi leadership.

Bush added that millions of Americans are praying for the armed forces now in the Middle East and that the liberated Iraqis will recognize the "honorable and decent spirit of the American military."

As he has many times, Bush declared that the United States has "no ambition in Iraq except to remove a threat. Our forces will be coming home as soon as their work is done."

White House spokesman Ari Fleischer had announced Bush's plans to speak on short notice.

Fleischer spoke as anti-aircraft fire and explosions were heard across Baghdad after air raid sirens went off at the capital at dawn.

A U.S. official declined to say whether the attack was successful.

Fox News' Bret Baier and the Associated Press contributed to this report.