Support for the Afghanistan war has risen eight percentage points since this time last year, according to the Washington Post-ABC News poll.
Thirty-eight percent of respondents said the war has been worth the costs, up from only 30 percent in December 2013, and 28 percent that July.
But overall, most Americans - 56 percent - still believe the 13-year-long combat mission has not been worth fighting, a disapproval rate that dates to 2010 in Post-ABC polls.
"The bounce-back in positive views is driven by a dramatic reversal of opinion among Republicans," said The Washington Post. "Only 39 percent of Republicans said the war was worth fighting in late 2013, but 56 percent believe so today, marking an end to a massive downward slide since 2009. In the early months of Barack Obama's presidency, as many as 77 percent of Republicans said the war was worth fighting."
Democratic support for the war increased by only one percentage point since 2013, from 30 to 31 percent. Independents also have a more favorable view of the war, moving from 26 to 35 percent.
A majority of Americans - 54 percent - support plans to keep thousands of troops in the country to help train Afghan forces and provide counter-insurgency assistance.
The number of troops in Afghanistan has fallen from a peak of 100,000 in 2011, to 10,000 in 2015, and is set to be halved by 2016.
When asked whether the Afghan war has made the U.S. more secure since the Sept. 11, 2001 attacks, 48 percent said it has made the U.S. more secure, while 47 percent said it has not. Only 19 percent said the war contributed a "great deal" to national security.
The poll was conducted Dec. 11-14 by telephone among a random sample of 1,000 adults, and has a margin of error of 3.5 percentage points.
