While both President Barack Obama and Prime Minister Benjamin Netanyahu made major efforts to emphasise the cordiality of their three-hour meeting in the White House on Monday, the differences between the two administrations over Iran were evident this week.
Mr Netanyahu arrived in Washington with the express intention of receiving an American commitment to a "red line" which would result in a military strike if Iran were to cross it.
He received clear and public assurances from President Obama and Defence Secretary Leon Panetta that the US would not allow Iran to reach a nuclear weapon capability, and that military force was an option if no other course worked, but the President repeatedly said that this was a last-resort option and that diplomacy and sanctions were the only way forward for the coming months.
The difference between the two leaders' approaches was clear in the contrast between the speeches each made this week at the annual convention of the pro-Israel lobby Aipac.
Mr Obama said there was "too much loose talk of war"; Mr Netanyahu said in his speech that "none of us can afford to wait much longer".
President Obama said repeatedly that military action was only a last-resort option
While the US President repeatedly mentioned the damage that a military strike could do to regional stability, his Israeli counterpart stressed again and again the risk of waiting too long, even comparing the current situation to the American reluctance to bomb the Auschwitz death camp during the Holocaust.
In their private discussions, Mr Netanyahu repeated his position that Israel reserved the right to decide on its own when and whether to attack Iran, but that a decision had not yet been reached.
Returning from Washington, members of Mr Netanyahu's entourage admitted that while Israel had not achieved all it had hoped to, the meeting was successful in that it had impressed on the Obama administration the urgency of the situation.
They also said that the Americans had both publicly recognised Israel's sovereign right to decide whether or not to attack and had agreed to supply Israel additional "bunker-busting" bombs and aerial tankers. However, it was unclear when these would be delivered and whether they would be relevant if a military strike on Iran were to take place in the coming months.
According to International Institute for Strategic Studies head John Chipman, Mr Obama assured Mr Netanyahu that "if Israel took US advice and did not attack prematurely...[then] when the threat matured, the US would, if all other options failed, use the military option."
On Tuesday, Mr Obama's position of giving extra time for diplomacy and sanctions to take effect was strengthened by the Iranian government's announcement that it was prepared to return to talks with the six powers - the five permanent members of the UN Security Council plus Germany.
Mr Obama also got a boost from the Iranian statement that it would allow International Atomic Energy Agency inspectors to visit the Parchin base, where it is suspected that military nuclear research is taking place.
Despite there not being a date or venue yet for the new talks with the Iranians, Mr Obama said on Tuesday that he hoped the talks would help calm "the drums of war".
Meanwhile, in a number of media interviews, senior Hamas officials in Gaza have said this week that they will not launch their missiles at Israeli targets if Israel attacks Iran. This is despite the fact that many of those missiles were supplied or funded by Iran.
While this is not yet official Hamas policy, it is another signal of the growing distance between the Palestinian movement and the Iranian-Syrian axis.
Hamas is now aligning itself with the Muslim Brotherhood that has taken control of the parliament in Egypt, and publicly distancing itself from Bashar al-Assad's regime in Damascus. With Iranian backing, Assad is massacring Sunni Muslims - with whom Hamas identifies. This still leaves the second most powerful organisation in Gaza, Islamic Jihad, which in recent months has become more favoured by Iran.