Portsmouth, New Hampshire (CNN) Following a rough week, Jeb Bush on Wednesday tried to aim the spotlight away from the decision to go into Iraq and focused it instead on President Barack Obama, sharply criticizing his decision to pull U.S. forces out of the country.

The former Florida governor, appearing at a business roundtable here, also called for a strategy to "take out" ISIS but did not go into specifics. He mostly argued that the war started during his brother's administration helped create stability in Iraq and since been unraveled because of Obama's policies.

"The focus ought to be on knowing what you know now, Mr. President, should you have kept 10,000 troops in Iraq?" said Bush, who's expected to announce his presidential bid in the coming months.

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In December 2011, the United States withdrew its final combat troops from Iraq, bringing an end to the nearly decade-long conflict that started under George W. Bush. The Obama administration asked for more troops to remain on the ground, but negotiations with the Iraqi government did not ensure that U.S. military personnel would be granted immunity.

Jeb Bush argued that Obama "could have kept the troops in and he could have had an agreement," adding "the United States had enough influence to be able to deal with the immunity issue."

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