Turkey scoped out at least three air bases in Syria where it could deploy forces as part of a planned joint defence pact before Israel hit the sites with air strikes this week, four people familiar with the matter said. The bombardment signals the risks of a deepening rift between two powerful regional militaries over Syria, where Islamist rebels have installed a new government after toppling former leader Bashar al-Assad in December. The Israeli strikes on the three sites Turkey was assessing, including a heavy barrage on Wednesday night, came despite Ankara's efforts to reassure Washington that a deeper military presence in Syria was not intended to threaten Israel.