[1/3] U.S. President Joe Biden leaves after taking part in the annual ceremony of pardoning the National Thanksgiving Turkeys on the South Lawn at the White House in Washington, U.S., November 20, 2023. REUTERS/Leah Millis/File Photo Acquire Licensing Rights Nov 23 (Reuters) - Americans celebrate Thanksgiving on Thursday with heightened security measures in place and tensions running high over the conflict between Israel and Hamas in Gaza, potentially casting a shadow over a normally joyous holiday. War in the Middle East has prompted officials to take extra precautions at airports and shopping malls across the United States and along the...