WASHINGTON -- Democratic presidential candidate Barack Obama yesterday announced plans for a midsummer trip that will take him to the Middle East and Europe for firsthand observation and consultations with foreign leaders while providing him an opportunity to bolster his national security credentials for the fall election against Republican John McCain.

His campaign said the senator from Illinois will visit Israel, Jordan, Germany, France and Britain.

Mr. Obama had said earlier that he would go to Iraq and Afghanistan this summer as well. No mention was made of those countries in yesterday's announcement, and campaign officials declined to discuss any aspects of those visits, citing security concerns. He last visited Iraq in January 2006.

The foreign tour comes amid questions about whether Mr. Obama is at a political disadvantage on national security issues against his Republican rival, who has a long resume of experience in those subjects both as a former naval officer and from more than two decades in Congress.

Mr. Obama has said he is eager to challenge the senator from Arizona and has made clear he is confident that, despite a brief tenure in the Senate, he can draw a favorable contrast with McCain on his command of the issues and the quality of his judgments. Democratic allies also believe the upcoming trip will offer a pointed message that he does not intend to cede foreign policy ground to his rival.

Mr. Obama was a staunch opponent of the Iraq war and used his opposition effectively, particularly in the early stages of the Democratic primaries, to put Sen. Hillary Rodham Clinton, who voted for the resolution authorizing the war, on the defensive. Now, as he prepares for his first visit to Iraq since January 2006, two forces are bearing down on his idea of troop withdrawal: a general-election campaign in which terrorism remains the Republicans' strongest issue and a relatively improved security situation in Iraq that many attribute to President Bush's troop buildup.

Both appear to be driving Mr. Obama toward a more measured exit strategy.