National defense is the job of the federal government.

A bank's defense, or any property owner's defense, would be that the adverse claimant hasn't met the state requirements for a valid claim.

The government control defense mainly because they have the means to control and give orders for defense purposes. The government's purposes is not only for the public welfare but also safety which is part of the defense purpose of the government.

the government bank is run by the state government and the nationalised bank is run by the federal government

A Government Bank is a bank that is fully owned by the ruling government of the country. It means that the government of the nation is the sole owning authority of the bank and it governs the functioning of the bank. Even if the bank declares bankruptcy the government holds the responsibility of returning all the money that was deposited by the customers.