When Ukraine get their F-16s they will get an advance in the air, without air support it's difficult for the tanks and ground troops.

Although Ukraine is struggling to contain Russia's latest offensive efforts on the frontline in the Donbas, at some stage Ukraine might decide to focus its offensive efforts on Crimea.

Most analysts believe Ukraine would struggle to liberate Crimea completely, but the strategically important port of Sevastopol is a centre of gravity for Vladimir Putin - something he will not want to lose.

Ukraine does not have a navy, but has successfully targeted the Russian Black Sea Fleet and pushed it further east.