LONDON // The largest security operation in the Irish Republic's history awaits Queen Elizabeth II today as she embarks on a historic, four-day visit to the country.
The Queen will be the first British monarch to set foot in Dublin since George V exactly 100 years ago - a time when all of Ireland was ruled from London.
Now, with terror attacks by nationalists increasing in Northern Ireland, which remains part of the United Kingdom, the security services fear the Queen's visit could provide paramilitaries with an irresistible opportunity for further outrages or, at the very least, publicity stunts and protests.
Leave has been cancelled for 8,000 police officers - 4,000 of whom will be on duty at any one time - and 2,000 troops who will guard the Queen.
Additionally, the Dublin government has taken the unusual step of giving permission for undercover, armed British police to patrol the streets throughout the visit.
Surveillance has also been increased on suspected republican dissidents and several arrests have been made both in Eire and Northern Ireland in recent days.
One of those taken in for questioning is believed to be the chief of staff of the Real IRA, the group blamed for the 1998 car bombing in Omagh that killed 28 people.
Also yesterday the veteran Irish militant Marian Price, 57, who served 20 years of a life sentence for bombing London in the 1970s, was returned to prison after the government revoked her parole licence. Price appeared at a rally last month at which masked gunmen threatened new attacks. She was charged under the Terrorism Act in connection with the rally.
The Irish government has even borrowed two water cannon from the Police Service of Northern Ireland to help cope with any rioting on the streets of Dublin.
Yesterday 500 troops sealed off the military airfield on the outskirts of the capital where the royal flight will touch down this afternoon.
Protests by groups wanting to see all of Ireland united as a republic are planned throughout the trip, in which the Queen will carry out engagements in Cork, Kildare and Tipperary as well as Dublin.
A security source in London said yesterday: "We are not so much worried about a direct attempt on the Queen's life although, obviously, we are prepared for such a possibility. But our main concerns centre on possible outrages or stunts by republican extremists intended to generate worldwide publicity."
Yesterday, British police said they received a warning of a bomb in London from an Irish republican dissident group and closed a major road leading to Buckingham Palace for several hours.
Caught up in the middle of all the security arrangements and road closures are Ireland's motorists and commuters. And they will find there is little relief even after the Queen returns to Britain at the weekend - the restrictions in Dublin are to remain in place because the US president Barack Obama is visiting next week.
But today, Enda Kenny, the Irish premier, is looking forward to the arrival of the Queen. He said he believes the royal visit would mark "the start of a new era" and remained confident that the Queen would be warmly welcomed by most Irish people. "The visit of the Queen is symbolically a healing of the past and facing with courage to the future," he added.
In an interview to be broadcast tonight by the state broadcaster RTE, the Irish president Mary McAleese will insist that the time is right for the first visit to the state by a British monarch since independence.
"I think it is an extraordinary moment in Irish history," she will say in the pre-recorded interview.
It is "absolutely the right moment for us to welcome on to Irish soil, Her Majesty the Queen, the head of state of our immediate next-door neighbours - the people with whom we are forging a new future, a future very, very different from the past, on very different terms from the past and I think that visit will send the message that we are, both jurisdictions, determined to make the future a much, much better place."
* With additional reporting by Agence France-Presse