WASHINGTON — Moments after making remarks in Jerusalem about Middle East culture that enraged Palestinians and undermined the public relations value of his trip to Israel, Mitt Romney looked around the room for Dan Senor, one of his campaign’s top foreign policy advisers.


It was Mr. Senor’s book about entrepreneurs in Israel that informed his comments, Mr. Romney explained to the group of Jewish-American donors he had assembled at the King David hotel. The book, “Start-up Nation,” is among Mr. Senor’s writings that Mr. Romney frequently cites in public.


Mr. Senor (pronounced See-NOR) has become one of the key people shaping Mr. Romney’s increasingly hawkish views on the Middle East. A television-savvy former spokesman for the American government in Iraq, Mr. Senor blends a foreign policy background, high-volume punditry and ties to wealthy hedge fund investors in the United States to become a triple threat as an insider in Mr. Romney’s presidential campaign.


His presence in the tight orbit of advisers around the Republican candidate foreshadows a Romney foreign policy that could take a harder line against Iran, embrace Jerusalem as the capital of Israel and move away from being the honest broker in the conflict with Palestinians.


But his views and influence have drawn new scrutiny to Mr. Romney’s Mideast positions, particularly after Mr. Senor said last week that Mr. Romney respected Israel’s right to pre-emptively strike Iran’s nuclear facilities. Campaign aides conceded that Mr. Senor got “a little ahead” of Mr. Romney on Iran, but said it had not diminished his role at the campaign.


“Dan is a long-term friend and adviser of Mitt,” said Beth Myers, one of Mr. Romney’s top strategists. “He’s consistently been a part of his foreign policy advising world. Mitt appreciated his advice and counsel on that trip and he remains a close adviser.”


By tapping Mr. Senor, 40, as his principal adviser on the Israel leg of his foreign trip this week, Mr. Romney passed over more seasoned strategists, some of them veterans of the Middle East peace efforts that have bedeviled presidents and diplomats for decades.


In Mr. Senor, Mr. Romney turned to an advocate of neoconservative thinking that has sought to push presidents to the right for years on Middle East policy. (His sister, Wendy Senor Singer, runs the Jerusalem office of the American Israel Public Affairs Committee, an influential lobbying organization.)


“Mr. Senor is a pragmatic hawk who clearly has an acute sensitivity and sensibility toward Israeli security interests,” said Aaron David Miller, a former adviser to Democratic and Republican secretaries of state. “That’s clearly a filter through which he, and should he get to be president, Romney, sees the whole panoply of issues in the Middle East.”


The plan for Mr. Romney’s overseas trip called for him to mix delicate global diplomacy with high-dollar campaign fund-raising, all on foreign soil. It would take an adviser accustomed to maneuvering effortlessly through the worlds of politics, money and news media.


Enter Mr. Senor, who has become one of Mr. Romney’s closest foreign policy advisers, having traveled three times to Israel with him. Mr. Senor began visiting Boston in 2006 to brief Mr. Romney, a former governor of Massachusetts, on foreign policy, and has had his ear since. In the acknowledgments of his book “No Apology,” Mr. Romney wrote that Mr. Senor sharpened his “appreciation of the dangers presented by the shift in our foreign policy.”


Mr. Senor declined to comment for this article.


But in Israel last week, the carefully laid plan was quickly consumed by negative attention. Gushing comments about Mr. Romney by Prime Minister Benjamin Netanyahu were initially overshadowed by Mr. Senor’s comments to reporters about Iran. When that died down, Mr. Romney’s assertion that cultural factors helped account for the wide Israeli economic edge over the Palestinians drew condemnation from Palestinian leaders.


For all the furor, Mr. Senor has proved to be a resilient public figure, often finding new success after public criticism.


At the start of the Iraq war, Mr. Senor served as the spokesman for the Coalition Provisional Authority, often delivering rosy accounts of the war’s progress to reporters whose on-the-ground view of the crisis there was anything but. Rajiv Chandrasekaran, a Washington Post reporter who wrote a critical book about the authority, once described Mr. Senor’s office as doing “a masterful job of spinning the media.”