BEIRUT, Lebanon — Amid the chaos of Syria’s civil war, Hezbollah has been moving long-range missiles to Lebanon from bases where it had stored them inside Syria, including long-range Scud D missiles that can strike deep into Israel, according to an Israeli national security analyst.

The analyst, Ronen Bergman, who has close contacts with Israeli intelligence officials, said Thursday that despite Israel’s undeclared campaign of airstrikes in Syria to stop new deliveries, most of the long-range surface-to-surface missiles given to Hezbollah by its allies Iran and Syria have been disassembled and moved to Lebanon.

American intelligence analysts have also concluded that members of Hezbollah, the Lebanese Shiite militia, are smuggling components of advanced Russian-made antiship missile systems piecemeal into Lebanon from war-stricken Syria to avoid an Israeli air campaign, a United States official said Thursday.

As many as 12 Russian-made antiship cruise missile systems may now be in Hezbollah’s possession inside Syria, according to the American official, who said that the organization had smuggled at least some components from those systems into Lebanon within the past year, but that it did not yet have all the parts needed there. The transfers were first reported Thursday night by The Wall Street Journal.