The third presidential debate tonight focusing on America's foreign policy will probably not have much impact on the race, two weeks before election day – and with an electorate much more concerned about economic prospects close to home than when exactly did Barack Obama acknowledge that the Benghazi 9/11 attack was an act of terror rather than a spontaneous reaction to the anti-Islam video. Debate moderator Bob Schieffer's decision to devote half the debate to Middle East-related issues (two-thirds if you include also the 15 minutes on Afghanistan/Pakistan) may also seem rather disproportionate, while China, with its major influence on the US economy, is only to be discussed in the final segment. And the eurozone and Mexico, both arguably affecting ordinary Americans lives to at least as great a degree as the Arab uprisings, are not even in the line-up.

But one issue to be debated in Boca Raton has the potential to play big in the election – just not the American one. Israeli politicians and strategists will be anxiously watching the third debate segment (entitled Red Lines – Israel and Iran). But it won't be for any inkling of how Obama in his second term or a new Romney administration would handle Iran's nuclear project – they know that election rhetoric has little relation to foreign policy once the campaign dust settles. Besides, they are in daily contact with both camps in Washington and know the current thinking. Their concern is much more immediate.

This will most likely be the last chance to hear a clear statement from either candidate, not only before Americans go to the polls on 6 November, but also in advance of Israel's general elections exactly two and a half months later. Never has an Israeli election been held so close to an American one, and the results of the electoral college are likely to have major implications on the tone and perhaps the outcome of the Israeli campaign. The strategic teams of the major Israeli parties, Likud and its rivals from the center-left, will be on the lookout for any usable quote that demonstrates either closeness or the slightest of differences between either of the candidates and the government in Jerusalem. Depending on the identity of the victor in two weeks, these quotes will be used accordingly in the ensuing campaign.

All the polling in Israel currently points to a clear victory for Prime Minister Binyamin Netanyahu, with the coalition of rightwing and religious parties upon which he can rely for support winning at least 60% of the vote. The center and leftwing parties are at war among themselves and none of their leaders is seen as a viable challenger to Netanyahu. Each of the parties is trying to attack Netanyahu and Likud on a different front – social inequities, bellicosity on Iran, religious special interests, the deep-frozen peace process – but none of these seem for now potent enough to prise enough voters away from the Likud and its partners to break Netanyahu's coalition-lock (a third of Israeli voters describe themselves as centrists).

American voters are in the position to give them a crucial lever.

In a recent poll carried out by the Maagar Mochot polling company for Bar-Ilan University on Israelis' attitude towards America, 69% said that the United States is Israel's loyal ally, opposed to only 10% who disagreed. An even more overwhelming 93% of Israelis agreed that the close relationship with the US is crucial for Israel's security. This unanimity among the general public is reflected also in closed briefings with senior military and diplomatic officials, who refer to the alliance with the Americans as "Israel's No 1 strategic asset", bar none.

But there is a slight cloud on this horizon. While 30% of Israelis believe that a President Romney would improve the two countries' relations, should he win next month, only 8% expect Obama to improve ties if awarded a second term. That doesn't mean Israelis dislike the president: 38% said in the poll that they have a positive attitude towards Obama; a similar proportion said they were neutral; and only 23% described their feelings towards him as negative. Just 15% feel he has been unfriendly to Israel during his first term.

The great majority of Israelis do not seem to think that Obama has something against them, quite the opposite. This is despite the bombardment of anti-Obama propaganda they have been under for the last five years, ever since the foundation of free newspaper Yisrael Ha'Yom (Israel Today), a well-financed daily that has become the country's most widely-read paper. The slavishly pro-Netanyahu paper, founded and bankrolled by casino mogul Sheldon Adelson, has been telling readers, basically from its first edition, that Israel cannot rely on the pro-Palestinian Democratic party. This is despite the current administration deepening security coordination and intelligence-sharing with Israel and financing Israel's new missile-defense system, the Iron Dome.

Adelson is estimated to have spent around $100m on his Israeli paper (political donations in Israel are capped by law, but a private newspaper is a convenient loophole). That is similar to the sum he has pledged the Republicans in their attempt to beat Obama. But it isn't just the mega-donor who connects Netanyahu to his GOP allies. Israel's prime minister, since the time he spent as a diplomat in the 1980s in the US, has been a trusted member of conservative circles.

He shares much of their worldview and fiscal principles, is beloved of Christian evangelicals and in his first term in office (1996-1999) incessantly quarreled with Bill Clinton. The last four years have been spent openly differing with the Obama administration, first on freezing settlement-building, and when Obama eased on that, shifting focus from the Palestinian issue to Iran. Netanyahu did not miss a single opportunity to belittle Obama's attempts to dissuade Tehran from pursuing a nuclear weapon through diplomacy and sanctions.

While Mitt Romney's reception in London this summer was hardly enthusiastic, on his next stop in Israel, he was accorded a head of state's welcome. And that included an intimate dinner with Prime Minister Netanyahu, each accompanied by his wife.

To date, Netanyahu's forceful policy on Iran has not harmed his popularity with Israeli voters. At the same time, successive polls indicate that the majority of Israelis do not support a military strike against the administration's wishes. While the differences between Jerusalem and Washington have been widely reported, Israelis do not fear for now that the relationship is in any way at risk. An open rift could be a potential game-changer.

It won't happen, of course, if Romney wins in two weeks: a Republican win could seal also Netanyahu's claim to electoral victory. Netanyahu would be free to bask in the shared glory after betting on the challenger when no one gave him a fighting chance.

A re-elected Obama, freed from campaign restraint, is another matter. He wouldn't have to change his policy even, just adopt a more censorious tone towards Netanyahu for a few weeks.

The prospect of re-electing a prime minister who is putting Israel's crucial strategic alliance at risk will make many Israelis think twice. Netanyahu, who is acutely aware of this possibility, has brought the elections forward to the earliest possible date, in the hope that two and a half months would not be enough time for Obama, facing the fiscal cliff, to launch new diplomatic initiatives.

Over the last two decades, the Israeli electorate has swung back and forth between right-, left- and centrist-led coalitions six times. At present, the opposition seems too fractured and leaderless to win over the centrist voters and unseat Netanyahu in this election. But the prospect of diplomatic isolation could lend them a rallying call – and perhaps, the only slim chance they are going to get.