BEIRUT, Lebanon — If a wealthy patron were all the Lebanese Army needed to counter the Shiite militant group Hezbollah as the dominant force in the country, the recent $3 billion grant from Saudi Arabia might make a decisive difference in the country’s complex political landscape.

But the Saudi aid package — nearly twice Lebanon’s $1.7 billion annual defense budget — is earmarked to buy French arms and is unlikely to give the army what it needs most, say supporters and opponents of Hezbollah here. And even if it does, they say, it will take years to make an impact.

And while the Saudis are clearly alarmed at Hezbollah’s staying power and its intervention in Syria’s civil war, analysts say the gift announced last week was intended as much to send a message to the United States as to shift the military balance.

Yezid Sayigh, a scholar of Arab militaries at the Carnegie Middle East Center in Beirut, said the Saudis were declaring a “tactical divorce” from the Obama administration over their frustrations with what they see as America’s indecisiveness on Syria and its attempts at reconciliation with Iran, Saudi Arabia’s regional rival and Hezbollah’s patron.