Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. AP Analysis: New Questions Arise as Iran Says It Downed Plane Associated Press DUBAI, UNITED ARAB EMIRATES - Iran's acknowledgement that it shot down a Ukrainian airliner, killing 176 people, raises new challenges for the Islamic Republic both externally amid tensions with the U.S. and internally as it deals with growing discontent from its people. The country did itself no favors by having its air-crash investigators, government officials and diplomats deny for days that a missile downed the flight, though a commander said Saturday that he had raised that possibility to his superiors as early as Wednesday, the day of the crash. While its paramilitary Revolutionary Guard took responsibility, the same commander claimed it warned Tehran to close off its airspace amid fears of U.S. retaliation for Iran's launch ofballistic missiles at Iraqi bases housing U.S. forces. That retaliation never came, but the worries proved to be enough to allegedly scare a missile battery into opening fire on the Boeing 737 operated by UkraineInternational Airlines. Wider tensions between Iran and the U.S., inflamed after Iran's top general was killed in Iraq by a U.S. drone strike January3, have for the moment calmed. However, President Donald Trump vowed to impose new sanctions on Tehran,and on Friday his administration targeted Iran's metals industry, a major employer. Meanwhile, thousands of additional U.S. forces remain in the Mideast atop of the network of American bases surrounding Iran, despite Tehran's demands that the U.S. leave the region. .