[kiiski]

It's very unlikely that he is there to actually guard anything. In most countries, outside a state of emergency or war, soldiers do not have any right to shoot citizens in the streets. Even if someone specifically attacks the soldier, the correct response is to back away and call the police to handle it.

He's just standing there either for ceremonial reasons or for training (possibly both). In any case, his only task is to stand there and call the police if there's trouble.

[johnnyhillbilly]

No, he's literally guarding the place. The correct response to an attack may involve inserting the clip, chamber a round and issue a loud warning before possibly firing.

An attack on the guard himself is likely to lead to a resolute counterattack.

Soldiers guarding typically have limited police jurisdiction of the area they guard in most countries.

This should be common knowledge.

[napoleond]

Both you and your parent commenter are sometimes correct, depending on the situation (believe it or not, laws vary from country to country, there are many different types of military groups in each, etc).

Your point of view is not always correct, so it should definitely not be common knowledge.