For moral, historic, and strategic reasons, the United States has Israel's back. Israel is the top recipient of U.S. foreign aid, and it has access to top-flight U.S. weapons its neighbors could only dream of. Probably most importantly, the U.S. — the world's sole superpower — is known as Israel's chief defender, both militarily and at the United Nations.

Making sure Israel is safe is a sacred, bipartisan, inviolable cornerstone of American foreign policy. But is it really so important that America be the nation that provides that protection? Israel and the U.S. are in a diplomatic rough patch right now, and maybe this is the time for both countries to re-evaluate their special relationship. Perhaps the two allies should take a breather and let another nation be Israel's global defender, at least for a spell.

The obvious choice is Russia.

Russia isn't the global superpower it used to be, but it's no slouch. Russian President Vladimir Putin's driving goal seems to be making Russia great again, feared or respected on the world stage, and that has involved putting ample resources toward rebuilding the country's military might — on top of its large arsenal of nuclear missiles. If Russia signed on, Israel could be assured of advanced weapons and enough nuclear backup to scare the daylights out of even the most hostile nation or nonstate group.

Secondly, while Russia's record with Jews has historically been pretty bleak — think pogroms — recent history is considerably brighter. The Soviet Union was one of the first countries to officially recognize Israel in 1948, and despite subsequent differences — the two nations were diplomatically estranged between 1967 and 1991 — Putin has worked to improve relations. He became the first Russian or Soviet leader to visit Israel ever in 2005, and made a return visit in 2012 to help inaugurate a memorial to the Jewish soldiers who fought in the Soviet Red Army in World War II.

There are lots of reasons for the improved ties between Russia and Israel, but key among them is the fact that Israel has become increasingly Russian in the past 20 years. Putin is deeply concerned with the wellbeing of Russian nationals wherever they reside, up to and including invading other countries to protect their interests, and 15 percent of Israelis are emigrants from the former Soviet Union.

Many of the these million or so members of the ex-Soviet diaspora still speak Russian, hang out with other Russian émigrés, read Russian-language newspapers, and frequent businesses that cater to Russian Israelis. About a third of them, 300,000, are considered Jewish by Israel's Law of Return — meaning they have at least one Jewish grandparent — but not by Israeli religious authorities, meaning they can't get married or buried in Israel, even though they are citizens.

Putin and Israel's government also share a hardline stance toward Islamic insurgencies and terrorism. Russia has been considered relatively pro-Palestinian, but Putin is notably more sympathetic to Israel's Palestinian crackdowns than his predecessors. Similarly, Israel declined to join the U.S. and Europe in criticizing Putin's harsh crackdown on Chechnya's Muslim militants, or even his incursions into Georgia and Ukraine.

Is that enough to convince Russia to become Israel's patron? Perhaps not, but there are other incentives, chief among them money and prestige.

Putin desperately wants Russia to be a world power again, to be consequential and at the center of major global decisions. The country that protects Israel is guaranteed a seat at the table when it comes to many of the biggest, most high-profile challenges in the global arena. Extending protection to Israel makes as much or more sense than hosting the Winter Olympics in a temperate Black Sea resort town, or (allegedly) bribing its way to hosting the World Cup. Financially, Russia is struggling with low oil prices and Western sanctions, and it's keenly looking for new markets for its armaments; Israel is a generous customer with a large defense budget.

If Russia could be convinced that taking over responsibility for Israel would also be a defeat for Washington, that would probably seal the deal. And in some ways, it could be a hard pill for the U.S. to swallow.

"If Russia could legitimately present itself as being on the side of Israel and against jihadist terror in the Middle East," writes Lincoln Mitchell at The New York Observer, "it would be much more difficult for American presidents to pass sanctions against Russia or try to bring its neighbors into NATO against Moscow's will if the American people, even if only a sizable minority of them, viewed Russia as a reliable friend of the Jewish state."

But passing off responsibility for Israel's safety to Russia would also benefit the U.S., and possibly the world. Right now, Moscow is the main protector of Syria's embattled President Bashar al-Assad and Iran — two countries that have hostile relations with Israel. Russia wouldn't necessarily have to stop supplying Iran and Syria with weapons and political cover, but it would have to at least moderate its support from them.

And while Russia hasn't been a very active player in the Israeli-Palestinian peace talks, the U.S. seems to have run out of steam as lead intermediary. Perhaps Moscow, given its historical support for the Palestinians, would be viewed by both sides as an honest broker. Barring that, Israel could at least have a freer hand to intervene militarily in the Palestinian territories without concern that its main global patron would criticize it on human rights grounds.

Israel and the U.S. have a long, close friendship, but as the band Chicago says, "everybody needs a little time away." There's no need to "consciously uncouple" entirely — Russia and Israel are already friendly, at least in a casual way, and the U.S. wouldn't become Israel's enemy — but if everyone would benefit from a Mideast realignment, there's no need to stay together for nostalgia's sake.

U.S. policy on Israel has been remarkably steady for decades. But it isn't carved in a stone tablet.