Should I use force?

Yes. You scrample fighter jets and force them down, using missiles if necessary.

Risk starting a war?

This does not follow. The war would be started by whoever illegally retaliated for a lawful arrest, not by whoever did the arresting.

Yes, you have air traffic control command them to land. If they don't, you escort them down with jet fighters. All that has occurred here is the ICC has shown that warrants can be situationally worthless.

Yes, you risk starting a war if you arrest a war criminal. That sucks. But that doesn't mean you ignore the warrant for fear of consequence. Now our fucking idiot president here gets a huge, very unneeded ego injection knowing European powers are afraid to arrest criminals going to speak to a convicted felon.

Yes landing the plane with force is literally the law.

Or even easier, don't give it flight space access. Flight space access is granted on request. Planes don't just simply show up above an airspace and hope to not get shot down. It's all with permission.

Netanyahu did not show up at the border unannounced saying "let me through or else". He got permission ahead of time. Had he not gotten permission, he would have had to find another country who did or gone around. Especially for Greece and Italy which don't really stand in his way, the Mediterranean is right there!

Even assuming that Netanyahu calls the bluff and flies through, there are a lot of options ahead of all-out war. For instance sending jets to "intercept" his plane and escort him out saying "he refused to follow orders to land and we did not deem it worth it to escalate the situation". It's not like his airliner is armed or anything. But it would send a very different diplomatic message.

For France in particular, this is far from the first time he flies over its territory unimpeded. This is not a matter of military concerns, this is pro-Israel Macron taking a stance to show support for his ally. He's not been very outspoken on Gaza because the domestic political situation is very delicate and anything he says can only weaken his support further, but his personal stance is hardly a secret and the military interceptors are under his full control.

Yes you can tell them you will arrest them if they fly over. And you should start a war.

Not sure what the point of joining the ICU if you don't want to hold the laws.

You withdraw fron icc. France and italy are in the nato, israel is not idiotic to start a war with the west