If the unthinkable happened that a nuke was detonated in the middle east–and US determined that their would be a retaliatory nuke strike—do we have the capability to shape the blast or size the nuke to fit the area?
Swiss manufacture it,French hoard it,Italians squander it,
Americans say it’s moneyHindus say it does not exist,
You know what I say-I say time is a crook–
peter lorre 1954
I’m no weapon’s specialist, but I’m sure you can adjust the size of the blast by using a particular megaton yield. Also, I’m sure detonating it at a certain altitude will give you different results, as opposed to at ground level.
But I think the idea of nukes aren’t necessarily in their scalpel like precision. 
BTW, is your OP radioactive or something?
No, and yes.
Most of our weapons these days are what are called “dial-a-yield” weapons.
What this means is that when used, the person arming it has the option of just setting off the unboosted primary (0.3 kilotons), the boosted primary (~ 1kt) or the entire thing (up to 1 megaton).
How convenient! If only everything was as easy as setting the yields on thermonuclear warheads.
And yet, setting the timer on a VCR…
What is this “VCR” you speak of?
I think the new standard of technological ignorance should be something like keeping your desktop background the default, or never changing your homepage…
I don’t know how much it would matter, given that the wind would eventually carry all the radioactive junk all over the place. It’s like trying to drop a precision fart in a classroom, it just doesn’t happen.
As others have said you can adjust the yield but I don’t think that there’s much you can do to alter the shape of the blast (although the terrain itself will do that to a certain extent). Regular chemical explosives can be shaped (and the casing of the device can be used) to direct the force in particular ways but you’d need a pretty hellacious material that could partially contain and channel the energy release of a nuclear weapon.
Depends on the yield and the altitude. A smaller airburst creates far less fallout than a large ground detonation.
As I understand it, it is possible in theory to shape a nuclear blast; you use several smaller nuclear bombs to shape the blast from a larger one with precisely timed shockwaves. That’s similar to the way some chemical shaped charges work, in fact.
The Orion drive in Footfall elevated a ship to orbit by detonating nuclear charges beneath it, with some sort of shielding in between the ship and the bombs. I realize that that was just science fiction, but were those nuclear blasts shaped? How else would the ship be given lift as opposed to simply being vaporized?
Just make the shielding between the ship and the bombs really strong and tough. It’s a difficult problem, but one amenable to brute-force solution.
It was a serious proposal at one point.
Its actually IMO technically quite workable.
Hell, in many ways its probably easier than building a reusable rocketship that has wings and lands like an airplane.