It's already underway, and already ballooning in cost. It started under Obama. $1.5 Trillion as a minimum[0].
Sentinel ICBMs, B-21 bombers, and Columbia Class SSBNs.
"The Air Force told Congress January 18 that the newly estimated cost of each LGM-35A Sentinel has jumped from $118 million in 2020 to $162 million today. That’s a 37% spike."
... The service’s original 2016 estimate for the program was $62.3 billion. Then it ballooned to $95.3 billion. The latest projection suggests its new cost could be nearly $132 billion."[1]
Sentinel ICBMs, B-21 bombers, and Columbia Class SSBNs.
"The Air Force told Congress January 18 that the newly estimated cost of each LGM-35A Sentinel has jumped from $118 million in 2020 to $162 million today. That’s a 37% spike."
... The service’s original 2016 estimate for the program was $62.3 billion. Then it ballooned to $95.3 billion. The latest projection suggests its new cost could be nearly $132 billion."[1]
[0]https://www.scientificamerican.com/article/inside-the-1-5-tr...
[1] https://www.pogo.org/newsletters/the-bunker/the-bunker-the-s...