US President Barack Obama and his Secretary of State John Kerry have a lot on their minds as they grapple with conflicts and political issues involving countries like Syria, Iran, Iraq, Sudan and Afghanistan - which no doubt must be causing a massive overload on their respective memory banks.Yet this would be a lame excuse for them forgetting about -- or seeking to minimize -- the existence and crucial importance of letters exchanged on 14 April 2004 between then US President George W. Bush and then Israeli Prime Minister Ariel Sharon, who died recently after languishing in a coma for seven yearsThese letters enabled courageous and highly dangerous decisions being taken by Sharon to kick start President Bush’s stalled 2003 Road Map - whose goal had been to end the Jewish-Arab conflict by 2005.President Bush's letter provided the catalyst -- and the political justification -- for Israel unilaterally evacuating the entire Jewish population of 8,000 from Gaza and withdrawing Israel’s army totally from there - without any preconditions or undertakings being sought from the Palestinian Authority.The presidential letter set out the framework that Bush would support in negotiations between Israel and the PLO - conditions that Obama cannot possibly now discard as Kerry finalizes his own framework agreement.President Bush’s letter clearly -- and unambiguously -- assured Sharon that:1. The borders of any Palestinian Arab State would not encompass the entire West Bank despite successive Arab leaders having demanded this outcome for the previous 37 years. 2. Jewish towns and villages in the West Bank would be incorporated into the borders of Israel.3. The Arabs would have to forgo their demand to be given the right to allow millions of Arabs to emigrate to Israel.4. Israel’s existence as a Jewish State would be non-negotiable.Bush's commitments to Sharon were approved -- almost unanimously -- by both the US House of Representatives and the Senate.It didn't take too long however for these Congress-endorsed commitments to be downplayed by Bush and his advisors.In an editorial -- published on May 14, 2008 -- former Jerusalem Post editor David Horovitz revealed the extent of the American resistance to remaining bound by President Bush's 2004 letter, following a meeting with Bush in the White House with a group of Israeli journalists:“Secretary of State Condoleezza Rice, however, has been known to minimize the significance of this four-year-old letter. Just last week, for instance, she told reporters that the 2004 letter talked about realities at that time. And there are realities for both sides….Bush’s National Security Adviser Stephen Hadley has also given briefings to the effect that Israel had tried to overstate the importance of a rather vague letter, which was issued at a time when Sharon was seeking to bolster support for the pull-out from Gaza. And in answering my question, Bush did not at first even realise that I was referring to the 2004 letter. Hadley, who was also in the Oval Office, had to prompt him. 'Okay, the letters,' the president then said, remembering.”This was far worse and more sinister than mere memory loss. An attempt was being made -- as early as 2008 -- to renege on America’s clear and unequivocal commitments given to Israel as the price for Israel’s total evacuation of Gaza.Israel had already paid a high price relying on Bush’s Congress-endorsed letter.Gaza had become a de facto terrorist state - with Hamas firmly entrenched as the governing authority.Israel had -- since its evacuation of Gaza in 2005 -- been subjected to a sustained barrage of rockets and mortars fired indiscriminately into Israeli population centers from Gaza by a bewildering variety of terrorist groups and sub-groups who would have had no chance of operating so freely from Gaza if the Israeli army had remained there.Former Prime Minister Ehud Olmert -- who succeeded Sharon -- had neither forgotten nor overlooked the critical significance of President Bush’s letter when agreeing to resume negotiations with the Palestinian Authority in 2007.At the international conference held in Annapolis in November 2007 to announce a breakthrough in the resumption of those negotiations - Olmert told Bush and the world leaders gathered there that:“The negotiations will be based on previous agreements between us, UN Security Council Resolutions 242 and 338, the road map and the April 14, 2004 letter of President Bush to the Prime Minister of Israel.”The subsequent failure of those negotiations can be directly attributed to the Palestinian Authority's refusal to countenance the Bush commitments made to Sharon. As Obama gets ready to approve Kerry's framework agreement, he and Kerry need to have their memory banks updated to remind them of the importance of honoring Bush's commitments. Any attempt by Obama and Kerry to resile from or circumvent Bush’s Congress-endorsed commitments to Sharon will torpedo any prospects for success in the current negotiations - leaving Obama and Kerry with no one but themselves to blame for bringing the current negotiations to an ignominious end.The idea that any American President would not consider himself bound by the written commitments of a former president -- as endorsed by Congress -- would undermine America's very democratic foundations.Disavowing the Bush commitments would prejudice the integrity of American diplomacy world wide - ensuring any political decisions by the current administration would not be worth the paper they are written on.Sharon has left behind a bitter pill - which Obama and Kerry must reluctantly swallow.Congress will be there to make sure they do.