Large areas of the country are affected by severe drought. Most of the grain harvest will die as a result. (UNLESS) → .............................

Unless large areas of the country were affected by severe drought, most of the grain harvest would not die./Most of the grain harvest would not die unless large areas of the country were affected by severe drought./Unless large areas of the country were affected by severe drought, most of the grain harvest wouldn't die./Most of the grain harvest wouldn't die unless large areas of the country were affected by severe drought.