evidence: BEIRUT — The commandos infiltrated Syrian rebel-held territory near the Lebanese border, watching rebel fighters come and go from a two-story villa before slipping inside to plant a powerful bomb. [...] In Syria, the turning point in Hezbollah’s strategy came after the group helped secure the Syrian border town of Qusair last June, said the Lebanese officials, who spoke on condition of anonymity to discuss Hezbollah military tactics. After that battle, they say rebels ambushed and killed four elite Hezbollah fighters. Now, Hezbollah sends small groups of fighters to observe areas before entering, the officials say. One official said Hezbollah also has linked Syrian territories where it is present to its bases in Lebanon via a secure, hard-wired telecommunication network it has been using back home for years.