WASHINGTON – Mitt Romney auditions on the international stage this week as he travels to England, Israel and Poland looking to establish credibility as a potential commander in chief in his challenge to President Obama.

For the Republican presidential hopeful, it’s a chance to demonstrate competence in settings often occupied by presidents. He’ll hold formal meetings with foreign leaders, give public speeches and visit historic sites.

Aides say it’s a chance for the candidate to forge links with strong U.S. allies and show that he’ll stand up for shared values.

“This trip is an opportunity for us to demonstrate a clear and resolute stand with nations that share our values and possess the fortitude to defend those values in the name of a more peaceful world,” said Lanhee Chen, Romney’s policy director.

There’s also risk: Romney, sometimes prone to misstatements, faces higher stakes wading into delicate diplomatic disputes than he does on the more familiar campaign trail at home. And executing a complicated trip through three countries over a weeklong span presents the most difficult logistical challenge Romney’s campaign has yet faced.

The centerpiece of the trip is a politically delicate visit to Israel, where he meets with top leaders who are closing in on a critical decision about whether to launch a military strike on Iran that is opposed by the Obama administration. The relationship with Israel and the question of what to do about Iran’s suspected nuclear weapons ambitions represent one of the starkest contrasts between Obama and Romney, who mostly has defined his foreign policy largely in terms of his opponent.

“If we re-elect Barack Obama, Iran will have a nuclear weapon. And if you elect Mitt Romney, Iran will not have a nuclear weapon,” Romney said last year at a GOP primary debate focused on foreign policy.