Coming Up on 'This Week,' Sen. John McCain

Plus roundtable debate on the state of the 2012 GOP field.

WASHINGTON, June 17, 2011— -- Sunday on "This Week," Sen. John McCain has a stern message for those who want to succeed him as the GOP nominee for president. Christiane Amanpour sits down with the former Republican presidential candidate from Arizona and finds out why he is so troubled by what his party's leaders are saying about U.S. national security policy.

The top Republican on the Senate Armed Services Committee weighs in on withdrawing troops from Afghanistan, what should be done about Libya's Moammar Gadhafi and whether a war-weary nation can tolerate another potentially long conflict.

Then, the relationship between the United States and Pakistan gets even more difficult. After the successful mission to kill Osama bin Laden, and the recent detention of Pakistani informants who provided tips to help find the al Qaeda leader, can the two countries rebuild trust? Is Pakistan a reliable partner in the fight against terrorism?

Pakistan's ambassador to the United States, Husain Haqqani, comes to "This Week" to discuss the way forward in this important relationship. What are the implications for the war in Afghanistan? And what is the path to stability in the wake of the Arab uprisings? Elizabeth Cheney of Keep America Safe and David Ignatius of the Washington Post join the conversation.

Plus, the Republican candidates took the stage this week for their first major debate in New Hampshire. Who came out on top? Which candidate had the best showing and which one had the worst stumble?

Our powerhouse political roundtable with George Will, ABC News Political Director Amy Walter, ABC News Political Analyst Matthew Dowd and Slate magazine's Jacob Weisberg discuss the debate and all the week's politics.

All that and Robin Roberts of "Good Morning America" with her special Father's Day interview of President Obama, Sunday on "This Week with Christiane Amanpour." You won't want to miss it.