We had a whole 20 minutes of warning for an ICBM attack. Although Soviet SLBMs off our coast reduced our warning to much less, those missiles weren't a threat to our ICBMs and so did not threaten the survivability of our nukes. Plus, the point of direct contact with the Soviet Union was centered on German territory. In conventional war, neither American nor Soviet core territory was under threat so pressure to escalate wasn't quite as bad. Plus there was the chance of an intermediate stage of theater nuclear war in Europe that still spared our territory until saner head prevailed. Plus, we had lots of weapons on a triad of land-, sea-, and bomber-based nuclear weapons to increase survivability. Although obviously, if deterrence failed despite all the nukes we had, the consequences would be a lot worse.
So Pakistan and India are trying to limit escalation dangers where they can:
Pakistan and India on Sunday exchanged lists of their nuclear sites under an accord which prohibits both sides from attacking these locations, the foreign ministry in Islamabad said.
Under the 1988 agreement, the nuclear-armed neighbours are required to submit the lists of all their respective nuclear installations and facilities -- civilian and military -- on January 1 every year.
India and Pakistan have none of these advantages. Conventional war immediately takes chunk out of their national territories (especially Pakistan whose capital is very close to the border). Flight time for missiles flying back is short. And the relatively small number of land-based nukes each has makes the temptation to preemptively strike the others nuclear arsenal pretty high. So fear of being on the losing end of a nuclear exchange will be high and mistakes could be fatal. Every enemy move could be interpreted in the frame of mind that the enemy is trying to disarm their nuclear force.
While geography is fixed, the Indians and Pakistanis are at least trying to lessen the chance that attacks on military sites for conventional reasons will be interpreted at planned preemptive strikes against a country's nuclear force because (unknown to the attacker) the sites have nuclear weapons, too. Now, each side knows what to avoid hitting to reduce the chance that fear will lead to nuclear escalation.
Of course, this means that each side essentially has a green light to go after undeclared nuclear sites. And the mere discovery that the other side has undeclared sites during a war or a crisis would lead the other to worry about just how many undeclared nuclear sites the other side has. So fear could be multiplied by betrayal.
Still, you do what you can. Each side really needs subs for a survivable nuclear deterrent from their local point of view. Although the thought of a Pakistani sub whose crew is taken over by Islamists makes me rather have the current situation. India probably feels that way, too.
Actually, I wonder if geography is as fixed as I assumed for the purpose of nuclear weapons. Could India lease an island in the southern Indian Ocean to deploy ICBMs to provide some distance from land-based Pakistani nuclear missiles? Could Pakistan do the same? Or might Pakistan deploy nuclear missiles to Saudi Arabia beyond short flight time from Indian bases? Would the Saudis risk nuclear war with India in order to have a fast nuclear deterrent against a nuclear Iran?
All the complications of proliferation in contrast to the relatively simple US-Soviet balance do not give me confidence that the world can avoid a nuclear war somewhere. That keeps me behind efforts to build anti-ballistic missile defenses no matter how long the road is. And even small steps to enhance survivability of Indian and Pakistani nukes are welcome. You never know what will be enough to restrain the temptation to escalate to nuclear war.
