Secondly, any encroachment by the Lebanese army on Hezbollah's area of influence in southern Lebanon will be fiercely resisted. While Hezbollah is widely portrayed as an Iranian proxy in Western media, the reality is that the Shite population of Lebanon sees them as a legitimate defense force, and only those Lebanese completely blinded by wishful thinking believe that more hardware would allow the Lebanese army to rout Hezbollah military forces.
Thirdly, what impact will internecine violence in southern Lebanon have on the relative stability that has obtained on the Lebanon-Israel border since Hezbollah forced the end of the Israeli occupation of southern Lebanon? Even Lebanese who are not Hezbollah supporters understand that the Israeli withdrawal was a Hezbollah victory for all Lebanese, not just the Shia.
Finally, while three billions may buy a lot of deadly hardware, the generosity of the Saudis can only have the effect of stimulating reciprocal generosity on the part of Iran and Russia, who have thus far shown no inclination to back away from their support of Assad. This Saudi gesture will inevitably lead to a massive escalation in the regional arms race.
Given that the Syrian conflict is already leaking across Syria's borders on all sides, such an influx of weaponry will all but guarantee a regional conflagration that is bound to engulf not only Lebanon, but Turkey, Jordan, and Israel as well.