WASHINGTON (AP) — Sometimes it seems as if Republican presidential contender Mitt Romney has two running mates. There’s Wisconsin Rep. Paul Ryan to help him out on budgets, deficits and other domestic matters. And then there’s Israeli Prime Minister Benjamin Netanyahu on foreign policy.

Netanyahu has been injecting himself into the U.S. presidential race big time. It’s extremely rare, almost unheard of, for a foreign leader to do that. Most, in fact, try their hardest to run the other way.

A personal friend of Romney since they worked together in Boston financial houses as young men, the two seem to see eye to eye on many U.S.-Israeli issues.

And Netanyahu increasingly has been critical of President Barack Obama’s failure to publicly declare a “red line” that Iran should not cross. He thinks that “red line,” if crossed by Iran, should trigger a U.S. military response.

His involvement seemed to reach a high degree of intensity over the weekend as the Israeli prime minister, who spent much of his childhood in the Philadelphia suburbs and graduated from the Massachusetts Institute of Technology, appeared on several Sunday TV news shows.

Asked on NBC’s “Meet the Press” whether Iran already had crossed his “red line,” Netanyahu used a football reference to answer:

“They’re in the red zone. You know, they’re in the last 20 yards. And you can’t let them cross that goal line. You can’t let them score a touchdown.”

“This is a matter of urgency,” he told CNN, calling on Obama to take the kind of action President John F. Kennedy took in giving the Soviet Union an ultimatum during the Cuban missile crisis.

Noting that Obama has said that it would be unacceptable for Iran to possess nuclear weapons, Netanyahu said, “If you’re determined to prevent Iran from getting nuclear weapons, it means you’ll act before they get nuclear weapons.”

While foreign leaders have not made a habit of getting involved in U.S. elections, Soviet leader Nikita Khrushchev bragged to Kennedy that “We elected you.”

When Kennedy asked what he meant, Khrushchev said the Soviet Union expressly decided to wait to release captured U-2 spy plane pilot Gary Powers until after the 1960 election to keep the Republican candidate, Vice President Richard Nixon, from claiming he could deal better with the Soviets.

Romney and Netanyahu are “two peas in a pod,” said U.S. historian Douglas Brinkley of Rice University. “And, after all, nobody’s going to write a history of the close friendship between Netanyahu and President Obama.” Their relationship has been cool.

Brinkley said it’s rare for foreign leaders to get involved in U.S. elections since British leaders tried to intervene in the process in the early 1800s. But he also said he’s noticed that “world leaders who went to college in the United States seem to feel a special kinship to America, and often a feeling that they should interject themselves.”

“Yet if President Obama interjected himself into an Israeli election, all hell would break lose,” Brinkley said.

“Leaders keep their eye on each other, but they try to stay away from each other’s national politics,” said Stephen Hess, a presidential scholar at the Brookings Institution.

Romney has said he’d chart his policy toward Israel, if elected, by studying everything Obama has said or done — and doing the exact opposite.

Yet, despite such rhetoric, Obama and Romney seem to both be saying much the same thing on the subject of a “red line.”

Obama says his red line is “that we’re not going to accept Iran having a nuclear weapon” — without being more specific.

And Romney recently told ABC News: “My red line is Iran may not have a nuclear weapon. It is inappropriate for them to have the capacity to terrorize the world.”

However, Romney in campaign speeches frequently claims that Obama has turned his back on Israel and is too soft on Iran.