Is It Easier to Prosecute War Crimes?

Grave breaches regime puts obligation on very state to search for and prosecute or extradite these people. Any eukranian general, a begar pardon russian general, who is culpable of war crimes can be arrested in the united kingdom at any stage. One needs to know which generals were in arge of witch troops on which days and in which parts of ukraine. But that's relatively easy, i would have thought, for a prosecutor to work out. And we not we. We're comein in a new era in some senses, aren't we, in respect of prosecutions for war crimes and crimes against humanity?