#1: The question is very narrow and allows for wide spectrum of possibilities. Additionally, term “country” in this situation is very shaky and one could fill-up 10 pages only on discussion what is “country” in this case and who is - legally - fighting here. I find questions like this a slippery-slope used by trolls. No offence, just my reading of the question that I find irrelevant to the whole mess.
#2: Croatian city of Vukovar was flattened by Milosevic army. In strict army terms to get rid of a guy who is shooting from a house window a tank needs to destroy 3 to 5 houses to neutralize one guy. However, destruction of Vukovar is one of the most barbaric and hineous acts in the former Yugoslavia wars because politicians and war machine put army in that situation and approved orders of a mass destruction. Asking a question like “what would you tank to do?” is pointless. There is no debate on how should Milosevic army approach the problem - they should not have been there in the first place.
Same goes for your question.
#3: Again terminology. It is amazing to me that attacking defensless people and taking away their land through constant warring you call “protecting” citizens. Just like US attacking Iraq was not protection of US - even though some still argue about it. Similarly I do not accept that attacking Gaza is for protection of citizens of Israel; if anything it either keeps the level of nervousness at the same level, provides for a brief exhiliration of the populus and keeps everybody on their toes until next time. It’s called cycle. I have no rational answer to a question like that. I’m honestly at a loss with words.
BTW, “protection of citizens” is the oldest trick in the books but it works. Every time.
#4: In case you missed it, the current events were triggered by IDF. There was a cease fire and then there wasn’t.
#5: While I understand the need to look up the international law, if you ever happen to study law you would realize that massive body of work and results are being constantly updated. It is almost a “law” that laws always look at the history to prescribe the future. However, laws cannot win when faced with th ecreativity of the people bent on doing what they think is “right thing to do”.
For example, in WWII japanese-americans did not need to be interned in camps in Guantanamo, if you catch my drift.
So direct answer to your question is I dont know where do you need to lookup. It may sound tardy, but sometimes looking deep inside of your soul is always good. For starters at least.
My expirience comes from not so recent history where in Sarajevo, Serbs had snipers shooting randomly at the people going bout their way in the occupied city. I did not need to lookup any law to understand that it is a war crime.