I need some help identifying a book that I read in the late 90s about a group of terrorists taking over a domestic missile silo, maybe in Colorado or thereabouts.

From what I remember as the group was assaulting the silo one of the Officer's managed to throw his keys into the safe and lock it, so the terrorists kidnap a welder from the local town to cut through the door.  While he's cutting a group of special forces assemble and assault the silo to regain control with a civilian of some kind along with them, for what reason I don't remember.

This ringing any bells for anyone?  I'd like to read it again...

Day Before Midnight by Stephen Hunter

this

That's it, thanks!  Fast response lol.

In many ways, his best book.

Yep.
Possibly his best with the exception of "Point of Impact".

A secret missile silo.
A rogue Russian commando group.
A kidnapped master metal cutting expert.
A multi-ton block of titanium.
A key to Hell
And two Vietnam tunnel experts.  One an American tunnel rat doing hard time in prison, the other an insane Viet Cong woman.

Yup, it's a good book!  I still like Point of Impact the best, but Midnight is my next favorite of his.

No, "The Third Bullet" is Hunter's best, to date.

Holy crap. My dad told my brother and me about this book when I was a kid, and then years later when I asked him about it, denied the whole story, and completely forgot about the book. I've been looking for this story for years. Thanks OP, I was beginning to wonder if my brother and I had imagined the whole thing.

I cast this book.

Duvall as the Russian General.

Tommy Lee Jones as Chargin' Charlie.

Pitt as the Spetnaz commander.

Michael Biehn as the Delta commander.

Tom Hanks as the FBI agent.

Clooney as the A10 pilot.

Samuel Lee Jackson as the tunnel rat.

Denzel as the black Delta operator.

Helen Hunt as the Welder's wife.

Ed Norton as the welder.

Michelle Yeoh as the VC tunnel rat.

Tim Roth as the Key dropper.

Written by Tarantino/Hunter.

Directed by Michael Mann.

Scored by Hans Zimmer.