That much is known.
For ten days rumors have been flying and various explanations have been offered as to what was really going on in this night time battle.
The most credible one is that Israel wanted to test Syria's new Soviet supplied air defense system, note how the administration calls it 'Iranian' in this AP story. Contrary to the Forbe's article, Iran also has new modern Soviet air defense systems. Debka speculates, but doesn't call it rumors, that both Iran and Syria have the anti-air systems only confirmed in Syria.
The newest speculation is that Israel was attacking a nuclear enrichment plant or nuclear weapons shipment supplied by North Korea!
These nuclear speculations seem least credible but the one the right is salivating over and fits in with administration plans to escalate tensions until an attack on Iran seems justified. Fox News, the propaganda arm of the GOP, is linking all Iraq, Syria developments together as part of the neocon justification for an attack on Iran.