( CNN ) -- President Obama delivered the commencement address Friday to the U.S . Naval Academy 's graduating class , speaking to an audience of 30,000 that included a former presidential candidate and proud parent of one of the graduates in attendance . Jack McCain shakes hands with President Obama at Friday 's commencement ceremony . John Sidney McCain IV , more commonly known as Jack , on Friday became the fourth McCain to graduate from the Annapolis , Maryland , service academy and the fourth with the same name . `` America , look at these young men and women . Look at these sailors and Marines . Here are the values that we cherish . Here are the ideals that endure , '' Obama told the crowd . About midday at the academy 's commissioning and graduation ceremony , McCain received a Bachelor of Science degree , taking the oath of office and being commissioned as an ensign in the U.S. Navy 103 years after his great-grandfather did the same . Watch Obama hug John McCain 's son » . With parents John and Cindy McCain watching , he shook hands with the president and then walked back into the crowd to applause and more hugs . Joe McCain told CNN that his brother plans to join his father and great-grandfather as naval aviators . `` His grandfather , JSM Jr. , was in submarines , commanding three different boats in World War II , '' he said . That grandfather later became Adm. McCain and was commander of the Pacific Theater during the Vietnam War , when Jack 's father , now Arizona Sen. John McCain , was being held as a prisoner of war in Hanoi . In an interview last year with GoMids.com , Jack McCain reflected on the advice his father gave him on the day he arrived at the Naval Academy . `` My dad told me there is one thing McCains are good at , and that is not giving in to pressure , and honor -- keeping our honor regardless of what happens , '' Jack McCain said . `` He then said , 'Do n't lie , cheat or steal -- anything else is fair game . ' `` John McCain , the Republican presidential nominee in 2008 , frequently poked fun at his record at the Naval Academy while on the campaign trail , pointing out that he `` stood fifth from the bottom '' of his class and racked up dozens of demerits . At a campaign event last October , McCain joked that Jack needed a `` DNA check '' because he had yet to receive a single demerit . ( Jack McCain told GoMids.com that he did accumulate some demerits -- for wearing flip-flops outside and forgetting to shave ) . McCain told Fox News on Thursday that his son is graduating `` in better class standing than I had , which was n't hard to do . '' `` I 'm very proud of him , '' he said . Meghan McCain , Jack 's older sister , sent a message on Twitter Friday saying her younger brother , Jimmy , could not attend because he is serving overseas . McCain told Fox News he is returning home this weekend . In his remarks to the students , Obama made a vow that he would not send them to war unless it is `` absolutely necessary . '' `` It 's a promise that as long as I am your commander in chief , I will only send you into harm 's way when it is absolutely necessary , and with the strategy , the well-defined goals , the equipment and the support that you need to get the job done , '' he said . `` This includes the job of bringing the Iraq war to a responsible end and pursuing a new comprehensive strategy to disrupt , dismantle and defeat al Qaeda and its allies in Afghanistan and Pakistan . '' Obama also promised additional assistance to military families , vowing that `` we will be with you every step of the way , increasing your pay , increasing child care and helping families deal with the stress and separation of war . '' And he said new laws will help ensure that veterans are well taken care of . Obama 's commencement address was his third and final of the year . He was also commencement speaker at Arizona State University and the University of Notre Dame .
Son of Sen. John McCain , the former GOP presidential candidate , graduates . Jack McCain shakes hands with Obama , who delivers commencement address . He is the fourth McCain to graduate from Naval Academy . Obama vows to not send them to war unless it is `` absolutely necessary ''