It is for the same reason why India and Pakistan will not nuke one another.
Granted, Iran does not have Nukes, India does so it is a bit different but here is what is not different.
Pakistan and India will not nuke one another because of close proximity, they are neighbors, same thing with Iran.
If the Pakistani government decides to nuke Iran, they will end up nuking themselves. Let's take a look at the map.
What is interesting is this is the first time Iran violated Pakistani airspace and as a result, they kicked out Iran's foreign minister to Pakistan.
Now that is a reasonable response by the Pakistani officials, nobody can blame them for that.
Granted, Iran does not have Nukes, India does so it is a bit different but here is what is not different.
Pakistan and India will not nuke one another because of close proximity, they are neighbors, same thing with Iran.
If the Pakistani government decides to nuke Iran, they will end up nuking themselves. Let's take a look at the map.
What is interesting is this is the first time Iran violated Pakistani airspace and as a result, they kicked out Iran's foreign minister to Pakistan.
Now that is a reasonable response by the Pakistani officials, nobody can blame them for that.
