Washington (CNN) -- If President Obama decides to send 34,000 more U.S. troops to Afghanistan, a new national poll indicates Americans would be split over whether to support such a move.
Half the people questioned in a CNN/Opinion Research Corp. survey, released Tuesday, said they would support such a decision, with 49 percent opposed.
But support for a troop buildup of that size is greater than the 45 percent of the public who support the war in Afghanistan. The survey indicates that 52 percent oppose the war.
"The war is unpopular, and previous polls have shown that Americans oppose sending more troops in the abstract," said Keating Holland, CNN's polling director.
"But it may be a different story when Americans are confronted with an actual decision, by the commander in chief, on a military matter. Previous presidents have seen a 'rally effect' -- at least temporarily -- when they have made command decisions like this one."
The poll's release comes after Obama met Monday night with his national security team on Afghanistan and neighboring Pakistan. It was the ninth meeting of the president's war council to consider whether to send more troops to Afghanistan, which the U.S. commander on the ground there has requested.
White House press secretary Robert Gibbs said Monday that Obama will announce his decision within days.
Sources said at one option presented to Obama calls for sending about 34,000 more U.S. troops to Afghanistan in addition to the 68,000 already committed to the country, with other options involving variations on that plan.
According to the poll, if the president decides to send a smaller number of troops than 34,000, 56 percent would oppose the move, with a little more than four in 10 backing the decision.
"Support for a smaller troop buildup drops most among Republicans," Holland said. "They appear most wary of doing things by half-measures in Afghanistan."
The survey also indicates that two-thirds of Americans said things are going badly for the United States in Afghanistan. That view is up 11 percentage points from March when 55 percent said things were going badly.
People questioned in the poll also were asked about the war in Iraq. Opposition to that conflict remains high, with 62 percent saying they oppose the war. But 57 percent said sending more troops into Iraq in 2007, known as the "surge," was a success.
The CNN/Opinion Research poll was conducted November 13-15, with 1,014 adult Americans questioned by telephone. The survey's sampling error is plus or minus 3 percentage points.