Prepping for World War III? US soldiers in choppers conduct 'realistic' urban combat training

Prepping for World War III? US soldiers in low flying choppers conduct 'realistic' urban combat training over San Diego - as shocked residents report hearing 'bomb-like booms' 

https://www.dailymail.co.uk/news/article-11713565/US-soldiers-low-flying-choppers-conduct-realistic-urban-combat-training-San-Diego.html