Dal Wall Street Journal:

"President Barack Obama's decision last week to use military force against Libyan leader Moammar Gadhafi's forces was made in part by his administration's fear that Western inaction could further embolden Tehran, these officials say.
Sunni-majority Saudi Arabia and Iran's Shiite government are locked in a battle for regional influence.
U.S. military planners are also concerned Iran could benefit from an overthrow of the monarchy in Bahrain, home to U.S. naval operations that help control the Persian Gulf's oil flow.
In Yemen, too, Washington's closest Arab allies, in particular Saudi Arabia, are worried the potential overthrow of President Ali Abdullah Saleh could strengthen Iran in the region(…).
"Everything the U.S. is doing to respond in the Middle East is colored by how this could hurt or help Iran," said a European official who has met with senior U.S. officials in recent weeks. "This might be an overreaction, but it's how people are viewing things (…).
An overthrow of Bahrain's Sunni monarchy would likely produce a government more aligned with Tehran's interests(…).
The Persian Gulf remains the most important flash point in the proxy battle between the U.S. and Iran. "We do expect Iran will attempt to take advantage of events for its own purposes," said Ben Rhodes, U.S. deputy national-security adviser for strategic communications. "Iran has a long history of attempting to meddle in the affairs of other countries."

Insomma, quando il gatto (americano) manca i topi (francesi ed inglesi) ballano. 
Sarà per colpa dell'overstretching e del deficit di bilancio, sarà per la mancanza di strategia dell'amministrazione Obama, sarà perchè Washington è sempre più focalizzata sull'Asia e l'Oceano Indiano, fatto sta che l'Italia dovrebbe riflettere molto seriamente sulla possibilità che il ruolo di "offshore balancer" degli USA nel bacino del Mediterraneo sia stia realmente attenuando. 
Ove così fosse (ed a mio avviso lo è) dovremmo pernsare seriamente a come attrezzarci per sostenere una competizione agguerrita.