Israel has no plans to attack Syria.
Do you think that if Israel found out that the captured soldiers where alive and being held in Syria they would ask the Syrian government to take them from Hezbollah and turn them over to Israel? I don't think Israel wants to start a war with Syria, but I see several situations where they would feel they have no choice.
I don't think either Israel or Syria wants to start a war, but neither wants to be seen as caving in either. Put two large and hostile military forces near each other and accidents happen. In the Middle East we have half a dozen that don't neatly line up into two sides. There are any number of ways it could blow up into a general regional war, and then possibly drag much of the rest of the world in.
Jay