Several major global cities are scaling back or enhancing security for New Year's Eve celebrations due to heightened concerns over terror threats and public safety. Precautionary measures include cancelling events like Paris's Champs-Élysées concert and Tokyo's Shibuya countdown, while others, like Los Angeles, are increasing security. These decisions follow foiled plots, such as an alleged bombing plan in Los Angeles, and recent violent incidents, prompting authorities to prioritize risk reduction for large gatherings.