WASHINGTON (CNN)  -- In their first head-to-head debate, Sen. John McCain criticized Sen. Barack Obama as a candidate who "doesn't understand" the key issues the country faces, and Obama linked McCain to President Bush on several issues. "I'm afraid Sen. Obama doesn't understand the difference between a tactic and a strategy," McCain said Friday as the two traded jabs over Iraq. Obama shot back, "I absolutely understand the difference between tactics and strategy. And the strategic question that the president has to ask is not whether or not we are employing a particular approach in the country once we have made the decision to be there."
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Barack Obama says John McCain wrong about Iraq
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McCain says Obama "doesn't understand" some key issues
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Candidates debate earmarks, taxes, economic plans
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Status of debate was in limbo until Friday afternoon
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