You don’t need a country to send an army into Israel to arrest Nethanyu and Gallant. If the ICC issues arrest warrants, then INTERPOL will issue a red notice. A red notice is an international arrest warrant and countries police forces that recognise the warrant can arrest using that warrant if the criminal is in their country.
INTERPOL are international police. They are not an army. It would not be an invasion. Their agents could go there and arrest them or Israel’s police can arrest them- if the government of Israel allows it.
INTERPOL law enforcement agents can follow them all around the world and arrest them almost anywhere.
https://www.interpol.int/en/How-we-work/Notices/Red-Notices/View-Red-Notices/
I think they are untouchable while still in government/power though, as they can simply instruct Israeli police to ignore the red notice and the border forces to not let in any Interpol agents.
Also, if the US wants to hide them in the US, then INTERPOL probably won’t find them.