Personally, I like the old “Rods from God” space based system.
“A satellite containing a magazine of tungsten rods and a directional thrust system. When a strike is ordered, the satellite would brake one of the rods out of its orbit and into a suborbital trajectory that intersects the target.
“As the rod approaches periapsis and the target due to gravity, it picks up immense speed until it begins decelerating in the atmosphere and reaches terminal velocity shortly before impact. The rods would typically be shaped to minimize air resistance and maximize terminal velocity.
“The Outer Space Treaty is designed to prohibit weapons of mass destruction in orbit or outer space; however, its text only prohibits nuclear, biological, and chemical weapons. Since the most common form of kinetic ammunition is inert tungsten rods, in most cases, kinetic bombardment is not prohibited by the treaty.”
I watched a video of one of those rods dropped by a high altitude AC blow apart a building in Iraq.