Understanding the nuclear Deterrence
Nuclear weapons are known as the last sword to save the country before falling into enemy's hand, Nuclear weapons are considered as weapons of mass destruction, since they destroy large volume of area, more than that it makes the land inaccessible for humans for more than centuries, due to the radioactive materials continuously emit radio waves which can harm humans.
Nuclear weapons are considered as suicide weapon. also a self defense weapon too, if the enemy nation too posses the nuclear weapon, it could be used for self defense. Both can use the nuclear weapons in case of anyone launched and vice versa. That's the reason why many nations instructed themselves by not using the nuclear weapons first. No first usage policy is commonly refereed term.
Meanwhile if the enemy nation do not have nuclear weapon, one can easily threaten the enemy with load of dossiers, just like how North Korean dictator Kim Jong repeatedly threatens the non nuclear pacific nations. Unlike in Indo-China-Pakistani theater all posses nuclear weapons. except Pakistan, India and China had nuclear weapons in safe hand and No first usage policy.
When comes to Pakistan, the rough terrorist regime, who threatens India with tactical nuclear weapons to counter the Indian cold start military movement doctrine. The doctrine simply understand as "March towards Islam-a-bad" . Pakistan reports they can stop the Indian forces using the tactical nuclear weapons if they crossed the border.
Here Pakistan has a less powerful nuclear deterrence compared to India. If Pakistan conduct a nuclear strike against India, with the barrage of some 40 to 60 missiles with nuclear warheads. India may face huge casualty and India can lost many cities.
One has to be understand, those known missile defense systems will not work effectively due to the barrage of multiple launches. Pakistan can use their low yield short range nuclear missiles over India. Pakistan can achieve 20% of successful launches. Since 80% of the missiles can be either intercepted by AD system or launch failure, or missile malfunctions.
In retaliation, India can launch another barrage of some 100 missiles over Pakistan each targets major Pakistani cities with the hit probability of some 80%. with the huge Strike from India, Pakistan can be pushed back to ancient age and can be inaccessible for another some 200 or more years.
The reason why India boosting it's conventional capabilities to fight against Pakistan, In the limited conventional war India can defeat Pakistan. even with low friendly causalities. However Pakistan can use their lands and peoples can live there without any issues even losing to India in a conventional war. the same not available if they planned for a WMD usage.
It's clear, Pakistan can continuously black mail India, while not performing a one, Since all those Pakistani nuclear missiles are always tracked by different nations Intelligence wing as well as Indian intelligence too. They were placed within the strike range of Indian fighter aircraft's. Suppose any conditions Pakistan tries to launch a nuke missile, India can conduct a preemptive air strike targeting those launch pads.
The same can be switched towards Chinese point of view, China has large conventional fire power as well as Nuclear fire power compared to India, India will not pose any serious nuke threats to China, since India knows then the outcome from China may larger than assume in an nuclear war. with the massive number of arsenal, China can take out more than 50 top cities in India, where India can take out some 20 to 25 Top Chinese cities with nuke strikes.
Results can favor to China only, where they can capable to withstand from Indian nuke attack but not us. Moreover China has large significant military fire power, while India too have, both maintain no first usage policy too. So the Indo China war could be in the conventional field only.
Those Arihant series also as part of nuclear deterrence, If massive first wave of Chinese nuke strike disabled all ground launching and air launching capability. Those Arihants can retaliate the Chinese launch, This is a example of Suicide weapon. On the other side, If India takes out Pakistani nuclear launching capability in first wave of attack, Pakistan has no option to retaliate. That Pakistan must understand before blackmailing India with nuke threats.