(CNN) -- Politics has returned to the water's edge. In the past week, we've seen how international events can suddenly dominate a political campaign, at least for a few days. The uproar in the Middle East over a YouTube video that featured anti-Islamic messages triggered widespread protests. An attack on the U.S. consulate in Libya left four people dead, including U.S. Ambassador Christopher Stevens. Protests in Egypt were equally intense as some people in a crowd of more than 2,000 scaled the walls of the U.S. Embassy. Protests spread to 20 other countries in the Middle East and beyond. In Tunis, protesters destroyed a school run by Americans while in Afghanistan protesters lit with a torch an effigy of Obama, the U.S. leader once hailed as the president who would repair America's image in the world, and watched it burn up.
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Julian Zelizer: Events have pushed foreign policy to front of campaign
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Zelizer: Turmoil in North Africa, Middle East could affect election's outcome
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International issues helped Eisenhower in 1956, Zelizer says
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Zelizer: Carter lost ground in 1980 after the surprise Soviet invasion of Afghanistan
But these crises only ended up bolstering the image of @placeholder as a strong commander in chief who could coolly guide the nation through crisis.