Had US President Barack Obama not invited Prime Minister Binyamin Netanyahu back to the White House for another meeting next Tuesday, then Netanyahu’s upcoming visit to Canada – and the warm reception he is expected to receive from Canadian Prime Minister Stephen Harper – would have highlighted stark differences between the Canadian and US administrations’ public treatment of Israel.Netanyahu and his wife, travelling to Canada on Friday for the first visit there by an Israeli prime minister in 16 years, are scheduled to be the guests Sunday at Harper’s summer residence in Ottawa. Harper asked for that extra time with Netanyahu, in addition to formal and official meetings he will have with the prime minister on Monday.There will be photographs and handshakes and press opportunities galore in Ottawa, a sharp contrast to the way Obama received Netanyahu in March: without photographers, without a joint appearance or joint statement, like an errant pupil brought into the principal’s office for a scolding.It is obvious to all that Obama is now trying to correct the unfortunate impression left from that last meeting, and the upcoming meeting in the White House is expected to be full of handshakes and smiles.But while the atmospherics of Netanyahu’s meetings with Harper and Obama are not likely to be startlingly different, the content of the talks, or what Netanyahu hears from the leaders, might still be.When Netanyahu sits across from Harper, he will be able to fantasize a bit about what it would have been like to have had George W. Bush, rather than Obama, as his White House interlocutor.Because to hear Harper on Israel is to hear echoes of Bush and his talking about the forces of light vs. forces of darkness, and how Israel is a beacon of democracy and a forward bastion of the western world in the Middle East.Harper, unlike Obama, is unlikely to counter any praise for Israel with an equal dose of praise for the Palestinians, or balance criticism of Palestinian violence or incitement with a blast at the settlements. In Canada both the tone and content of what Harper says will likely be very much to Netanyahu’s liking.In DC the tone will be much improved, but the content will not have shifted all that much. The Obama administration still believes very much in the land-for-peace paradigm; still thinks building in Ramat Shlomo is an Israeli provocation; still wants to see all settlement building stop; and still thinks that there is linkage between solving the Palestinian-Israeli conflict and halting Iran’s nuclear ambitions.Those points, more than just irritants in the relationship between Washington and Jerusalem, have not dissolved simply because Obama – this time – will meet Netanyahu with a public smile.But don’t discount the smile. It is important not only for Obama because of domestic political considerations, but also for Israel. The manner in which a message is delivered is important, even if the content is not that different.When the Palestinians see Obama treat Netanyahu shabbily, then they can leap to the conclusion that the US is exasperated with Israel, and it is just a matter of time before Washington turns the screws another notch and “delivers” the Israeli government.But when they see Obama interacting cordially, maybe even warmly, with Netanyahu, they will be less inclined to think that the US-Israeli honeymoon is over; less inclined to think that they don’t have to do anything, but can just sit back and wait until Obama shakes the tree and the ripe Israeli fruit falls gently into their hands.There are those who will say that the Obama administration’s sudden change of tone is insincere, an embarrassingly transparent function of Obama’s election politics. He needs Jewish money in his party’s election chest for the important midterm elections in November and he needs Jewish voters in key states.But so what? The change is there, the reason is secondary. And what this change demonstrates is that regardless of who sits in the White House, there is only so far a president can go in trying to recalibrate the US-Israeli relationship before certain checks come into play to keep the president “in bounds.” In short, a US president’s ability to “turn the screws on Israel” is limited by certain backstops that exist. One of these backstops is the active and visible presence of people – Jews, but not only Jews – in the political system for whom Israel is extremely important.New York Sen. Charles Schumer is a very important American politician, who could quite possibly – if Nevada Senator Harry Reid loses his election in November – be the next Senate majority leader. And Schumer, who is Jewish and a close Obama ally, is also unabashedly pro-Israel. He will only let Obama go so far in his treatment of Israel before he pushes back.Another backstop is the Jewish participation in the electoral process, both in terms of contributing massively to the Democratic Party, and voting. True, Israel is not the main election item for all Jews, but it is an important enough item for enough Jews to get the administration worried that they could lose them if the pressure on Israel remains at its current level.There are other checks as well that don’t exist, for instance, inplaces like Europe, where national leaders have wider berth in shiftingpolicy on Israel before coming up against any significant resistance.There is no strong Evangelical Christian voice in Europe, for instance,like there is in the US, and this group in the US would also complainloudly if it perceived that the president had gone too far.Schumer, in a radio interview he gave last month when he – for thefirst time – publicly questioned Obama’s polices on Israel, pointed outan interesting historic tidbit: many US administrations, at thebeginning of their terms in office, “have this idea to talk tough toIsrael and make nice to the Arabs and the Palestinians, and [believe]that’s the way to bring about peace.” Ronald Reagan, who Schumer characterized as “the best friend Israelever had,” had this approach and during his first two years wanted tosell AWACS to Saudi Arabia.Bill Clinton, Schumer said, made the same mistake at the beginning ofhis term, and “later became a very good friend of Israel. George Bushthe first did it and never got over it. We are at a crucial moment hereand I am hopeful that the administration will see the right way to go.I am working on it.” That Schumer is “working on it” is one of those US constraints in placeto preserve the close ties between the two countries. The dramaticchange in the Obama administration’s tone over the last few weeks showsthat these backstops are still there, and are still effective.