WASHINGTON — The United States and its Arab allies are knitting together a regional missile defense system across the Persian Gulf to protect cities, oil refineries, pipelines and military bases from an Iranian attack, according to government officials and public documents.

It is an enterprise that is meant to send a pointed message to Tehran, and that becomes more urgent as tensions with Iran rise. But it will require partner nations in the gulf to put aside rivalries, share information and coordinate their individual arsenals of interceptor missiles to create a defensive shield encompassing all the regional allies.

Secretary of State Hillary Rodham Clinton, among the first to raise the need for the missile shield three years ago, sought to spur the gulf allies on during a recent visit to Saudi Arabia.

“We can do even more to defend the gulf through cooperation on ballistic missile defense,” she said during a session in March of the Gulf Cooperation Council, which includes Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.