The Queen has spent her life sacrificing her own interests to her duty, so she will shake hands with Martin McGuinness uncomplainingly. Unlike the Sinn Féin leadership, she does not have the instincts of a diva. What Martin McGuinness does is what he and the other members of the oligarchy running the republican movement think is in the best interests of his party. What the queen does is what her democratic government thinks is in the best interests of her country.
The royal visit to the Republic of Ireland was planned and choreographed primarily by the Foreign and Commonwealth Office (FCO) and the Department of Foreign Affairs (DFA). The queen is treated with courtesy, so she will have been kept informed of progress by the Prime Minister at their weekly meetings and she'll have seen relevant official papers in the red boxes that are delivered to her every day of the year except Christmas Day and Easter Sunday. While she decided what to wear and the Palace had a significant input into her speech, everything will have been cleared by the FCO in consulation with the DFA. The Northern Ireland Office will be in the lead on this visit, but there will have been plenty of Irish diplomats working behind the scenes.
At some stage, David Cameron will have asked her if she was prepared to shake hands with Martin McGuinness in the interests of furthering the peace process. Of course in theory the queen could have thrown a wobbly and told him to get lost and the government could have done nothing about it, but that she would do so is inconceivable. She is not a puppet, but she sees herself as an instrument to further the interests of her people. Unless she was being asked to do something she thought morally wrong, she will have discussed it calmly, ignored her personal feelings and followed his advice. She will have the consolation that when in the Dublin Garden of Remembrance she bowed her head to the memory of people for whom she can privately have had little enthusiasm, the electric effect on Anglo-Irish relations was positive beyond the wildest hopes of the diplomats and politicians.
Only to her family, in private, will the queen have given any indication of what a big ask this is. It was the IRA that in 1979 blew up Prince Philip's uncle, Lord Mountbatten and his 14-year-old grandson, Nicholas Knatchbull. She will know that in 1984 Charles and Diana would have been assassinated had informer Sean O'Callaghan not scuppered the plot. One of her governments suffered fatalities in the Brighton bombing and another was mortared in Downing Street. Thousands of her subjects were murdered and maimed by an organisation McGuinness led and extols. But no more than herself would her family demur: 'The Firm' knows its job.
What will help the queen get through is her perspective. Think of some of those she's had to hobnob with in the past. Over the sixty years of her reign, she's had to smile and shake hands with people she knew to be ruthless dictators who murdered, tortured and looted their own people. So what's new?
Queen Elizabeth prizes the Commonwealth because she regards it as a force for good which encourages friendship between nations, races and religions, but it's had many unsavoury leaders. Consider Robert Mugabe, on whom her government required her in 1994 to confer an honorary knighthood for 'significant contributions' to relations between Britain and Zimbabwe. By 2008, the old monster's wickedness was such an open scandal that she stripped him of that honour because of his 'abuse of human rights and abject disregard for the democratic process'. Mugabe knew this snub was at her government's bidding. As he hurled abuse at the British government, he added that he continued to respect the Queen.
Outside the Commonwealth it's been much the same. She can't have been thrilled in 1978 to have the frightful Nicholae Ceausescu of Romania to stay at Buckingham Palace. He was already so bonkers by then that he brought his own sheets and a food taster and washed with rubbing alcohol after touching her. The honorary knighthood she had to confer on him at that time was removed in 1989 the day before he was executed by his disaffected countrymen.
She must be reflecting that Martin McGuinness is small beer after the tyrants she's had to shake hands with. She has a great sense of humour, but she will not yield to the temptation to ask him what he does. And however she's feeling inside, she'll do her duty with grace. I am no fan of McGuinness, but he lacks the vanity and pomposity of Gerry Adams. I expect him to behave like a gentleman.