CHARLESTON, S.C. (Reuters) - Republican presidential candidate Jeb Bush called for an increased U.S. troop presence on the ground in Iraq as part of a global coalition to take on Islamic State militants, shifting to a more hawkish stance in response to the Paris attacks.
Bush's decision, which will inevitably lead to comparisons to the U.S.-led invasion of Iraq ordered by his brother, former President George W. Bush, was reached after the attacks in Paris, where 129 people were killed by gunfire and bombs.
"Radical Islamic terrorists have declared war on the Western world. Their aim is our total destruction," Bush told a conference hall filled with gray-uniformed cadets at The Citadel, a military college in Charleston.
"We can't withdraw from this threat, or negotiate with it. We have but one choice: to defeat it."
Struggling to break into the top tier of candidates in the Republican field with Donald Trump and Ben Carson, Bush used an expansive national security address to present himself as ready to be commander in chief, saying the Paris attacks are a reminder that "we are living in serious times that require serious leadership."
Bush was vague on how many ground troops the United States should contribute to an international coalition that he says he would build if elected president next November.
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Presidential candidate Bush wants increased US presence on ground in Iraq
NORTH CHARLESTON, SC - JANUARY 15: Former Republican presidential candidate and South Carolina Sen. Lindsey Graham (R) announces his endorsement of Jeb Bush for president on January 15, 2016 in North Charleston, South Carolina. Graham dropped his bid for the presidency last month. (Photo by Scott Olson/Getty Images)
NORTH CHARLESTON, SC - JANUARY 14: Republican presidential candidates (L-R) New Jersey Governor Chris Christie and Jeb Bush laugh during a commercial break during the Fox Business Network Republican presidential debate at the North Charleston Coliseum and Performing Arts Center on January 14, 2016 in North Charleston, South Carolina. The sixth Republican debate is held in two parts, one main debate for the top seven candidates, and another for three other candidates lower in the current polls. (Photo by Scott Olson/Getty Images)
GRINNELL, IA - JANUARY 12: Republican presidential candidate Jeb Bush greets people during a town hall at the Brownell's Firearms Manufacturing company on January 12, 2016 in Grinnell, Iowa. Bush continues his quest to become the Republican presidential nominee. (Photo by Joe Raedle/Getty Images)
WAUKESHA, WI - NOVEMBER 09: Wisconsin Governor Scott Walker (R) sits with Republican presidential candidate Jeb Bush (L) at La Casa de Esperanza during a campaign stop on November 9, 2015 in Waukesha, Wisconsin. Tomorrow Bush will participate in the third Republican presidential debate sponsored by Fox Business News and the Wall Street Journal at the Milwaukee Theater in nearby Milwaukee. (Photo by Scott Olson/Getty Images)
TAMPA, FL - NOVEMBER 2: Republican presidential candidate and former Florida governor Jeb Bush allows a supporter to loosen his necktie during a rally on his 'Jeb Can Fix It' Tour on November 2, 2015 at the Tampa Garden Club in Tampa, Florida. Following dropping poll numbers and poor debate performance Bush is trying to reset his campaign that many say has been flailing. (Photo by Brian Blanco/Getty Images)
DES MOINES, IA - AUGUST 14: Republican presidential hopeful and former Florida Gov. Jeb Bush (R) and Iowa Gov. Terry Branstad eat a pork chop on a stick at the Iowa Pork Tent during the Iowa State Fair on August 14, 2015 in Des Moines, Iowa. Presidential candidates are addressing attendees at the Iowa State Fair on the Des Moines Register Presidential Soapbox stage. The State Fair runs through August 23. (Photo by Justin Sullivan/Getty Images)
DES MOINES, IA - AUGUST 14: Republican presidential hopeful and former Florida Gov. Jeb Bush (C) talks with members of the media as U.S. Sen. Chuck Grassley (L) (R-IA) and U.S. Sen. Joni Ernst (R) (R-IA) look on during the Iowa State Fair on August 14, 2015 in Des Moines, Iowa. Presidential candidates are addressing attendees at the Iowa State Fair on the Des Moines Register Presidential Soapbox stage. The State Fair runs through August 23. (Photo by Justin Sullivan/Getty Images)
MIAMI, FL - JUNE 15: Former Florida Governor Jeb Bush waves on stage as he announces his candidacy for the Republican presidential nomination during an event at Miami-Dade College - Kendall Campus on June 15 , 2015 in Miami, Florida. Bush joins a list of Republican candidates to announce their plans on running against the Democrats for the White House. (Photo by Joe Raedle/Getty Images)
MYRTLE BEACH, SC - MARCH 18: Former Florida Governor and potential Republican presidential candidate Jeb Bush kisses a supporter during an early morning GOP breakfast event on March 18, 2015 in Myrtle Beach, South Carolina. Bush announced in December that he 'actively explore' a presidential run in 2016. He is currently on a two day tour through South Carolina and will attend several fundraising events. (Photo by Richard Ellis/Getty Images)
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President Barack Obama has relied heavily on U.S. air strikes against Islamic State in Iraq and Syria but recently sent 50 more special operations forces to help identify targets. He has said a massive reintroduction of U.S. ground troops in Iraq would be a mistake.
Bush said while air power is essential, it is not enough.
"The United States -- in conjunction with our NATO allies and more Arab partners -- will need to increase our presence on the ground," he said.
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The effort will require "overwhelming force," Bush said, to take out Islamic State's self-proclaimed caliphate in parts of Syria and Iraq.
The scope of any increased U.S. presence on the ground should be in line with what U.S. military generals recommend and the bulk of the ground troops should come from "local forces that we have built workable relationships with," Bush said.
Iraq is a sensitive subject for Bush, given that both his brother and his father, former President George H.W. Bush, invaded the country.
Jeb Bush's plan calls for maintaining the U.S. prison in Guantanamo, Cuba, that his brother used for foreign terrorism suspects and which Obama is trying to close before leaving office in January 2017. The prison currently has 107 inmates.
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Bush is eager to make an impact in a Republican race that in some respects has been leaving him behind. He is in single digits in many polls with Republican voters more enthusiastic about non-politician candidates Donald Trump and Ben Carson.
Bush's belief is that voters eventually will come around to a serious, policy-minded candidate like him but with the Iowa caucuses to kick off the 2016 election season on Feb. 1, his plan has not helped him in polls.
A Reuters-Ipsos poll found on Tuesday that 33 percent of Republican voters felt Trump would be the strongest candidate to deal with terrorism, followed by Senator Marco Rubio at 17 percent. Carson and Bush were tied at about 9 percent.