A military analyst, Riyad Kahwaji, told Al Jazeera that Bush is trying only to reverse his state's policy on Iraq.
"Now, after nearly four years and all those casualties, support for the presence of US troops in Iraq has dwindled,” Kahwaji said from Dubai.
Bush is expected announce that he is adding about 20,000 US soldiers to the existing deployment of about 132,000 in his 9pm (02:00 GMT Thursday) speech, US politicians briefed on the plan said.
Kahwaji said that 20,000 US troops were unlikely to make a difference to the country’s overall security situation.
“The level of insurgency is higher than before and so is the possibility of civil war and if Bush’s obvious objective is to control Baghdad then 20,000 extra troops might be enough to clean up Baghdad of militia men. But they will need better luck with the rest of Iraq,” Kahwaji said.
A senior official said late on Tuesday that the additional US forces would be aimed at quelling violence in Baghdad, and said that the escalation would be gradual and "not all at once".
Opposition Democrats who control the US congress plan to hold a symbolic vote on the plan, the New York Times reported on Wednesday.
The vote will force legislators, especially those with Bush's Republican party, to go on the record over whether they support the new plan for the unpopular war.
Congress has no direct say on sending more troops to Iraq, since under the US constitution the president is the military commander-in-chief, and the executive branch is in charge of US foreign policy.
But a vote would increase pressure for Bush to find a quick end to the conflict.
Democratic leaders in congress have already announced a series of hearings into the conduct of the Iraq war, something the Bush administration never faced when republicans controlled Capitol Hill.
Bush's speech "is going to clearly show that he is calling for an escalation of the war", according to Harry Reid, the senate democratic majority leader. "The people of this country do not support an escalation."
More than 3,000 US troops have died in Iraq since the US-led invasion in March 2003 to topple Saddam Hussein and dismantle his supposed weapons of mass destruction.
A woman was killed and a male nurse shot dead in separate shootings in Mosul, in the north.
The woman died when gunmen opened fire randomly inside a central bus terminal. The nurse was killed in a raid on a private clinic in the neighbourhood of Qahira, a Mosul police spokesman said. Another two unidentified bodies were found in Mosul, he said.
In the Iraqi capital, four civilians were wounded in two roadside bomb attacks, one of which also ruptured a water pipe supplying the Shia slum district of Sadr City, an Iraqi security source said.
A civilian was killed and three wounded in the south of Baghdad, when a car rigged with explosives blew up at a petrol station in Mahmudiyah, an interior ministry source said.
In what has become a constant curse in sectarian-torn Iraq, the bodies of nine men aged between 20 and 30 were discovered in and south of Baghdad, their hands cuffed and their eyes blindfolded, police sources said.