Integrated air defence as in Moscow or Beijing. Actually very few countries have it. Even Western Europe doesn't have integrated air defence over most cities. As you can tell, integrated air defence is geographically limited and can be partly overcome by gliding munitions. PS. If you're planning to sortie over Moscow soon with your shiny Typhoons and SCALP, kindly inform here first so I can blow my savings on booze and top hookers in anticipation of world oblivion.