"Securing Your World" is G4S's maxim. But it looks like the world's largest security firm has failed to secure its own world, at least as far as London 2012 is concerned.
About 3,500 extra troops have had to be deployed after G4S admitted it would not be able to provide enough security staff for the Games.
Police have also had to deploy extra officers at short notice from eight UK forces to do Olympic security work after the company's staff failed to turn up to venues.
The fiasco has been embarrassing and has heaped pressure on Mr Buckles to quit. More than £400m has been wiped off the firm's value since the staff shortfall came to light.
Mr Buckles said he was "bitterly disappointed" at his company's failure to meet the terms of its contract, but said he would not step down.
"I have been here 27 years. I am very committed to staying. It just depends, doesn't it?" he told a newspaper.
Mr Buckles has described his leadership style as: "no excuses, please," and considers Margaret Thatcher his business hero.
His salary last year was £830,000, according to the firm's 2011 annual report.What is G4S?
G4S has 657,000 employees in more than 125 countries and makes its money from companies and governments outsourcing "businesses processes" - placing security staff where there aren't enough police, for example, or prison officers where those are lacking.
Government contracts accounted for 27% of its £7.5bn turnover in 2011, and it had hoped to have a bumper 2012 as a result of its work on the Olympics.
"We protect rock stars and sports stars, people and property, including some of the world's most important buildings and events" is how it presents its business - security made sexy, almost.
But G4S has run into difficulty with high-profile contracts before.
Last October, inmates in Birmingham Prison, under G4S's management since it became the first British prison to be transferred into private control, were locked in their cells for almost a day after a set of keys fitting every cell door went missing.
G4S runs seven prisons in England and Wales and is eyeing new business as police forces, under budgetary pressures, are looking to outsource to private sector companies.
The firm also made a high-profile bid in November to buy Danish rival ISS, only to abandon it following a shareholder revolt.
The botched take-over cost the company £55m, and raised questions about Mr Buckles' judgment of pursuing such a deal in the first place, as G4S had been already performing well.
Mr Buckles later said of the debacle that it was "one of the most bruising experiences of [his] life".
The conduct of G4S's security staff has also come under scrutiny.
G4S and three of its guards were investigated over the death of Jimmy Mubenga, an Angolan asylum seeker who died while being deported from the UK by G4S in 2010.
However, the Crown Prosecution Service said it would take no action against the three guards or G4S as there was insufficient evidence to bring any charges.Soldiering on
G4S is contracted by London 2012 organisers Locog to supply 13,000 staff to the Olympics.
The company, by its own admission, stands to lose up to £50m on the contract, worth a total of about £280m, after being unable to provide the 10,000 staff it had been contracted to deliver.
Now 3,500 British soldiers are being deployed at two weeks' notice to fulfil G4S's pledge to keep the games safe, and during the time many of them had planned to take their summer holidays.
Home Secretary Theresa May told the Commons that there was a clause in Locog's contract with G4S that sets out a penalty if they do not fulfil their agreed responsibilities, though she said that was a matter between G4S and Locog.