Prime Minister Tony Blair has attacked UK critics of his week-long trip to Africa, after receiving a warm welcome on his arrival in Sierra Leone.
Mr Blair was made an honourary paramount chief on his trip
Mr Blair's trip, just before he steps down as PM, has been dubbed a "vanity tour" by some UK newspapers.
But Mr Blair said: "The one thing I have come to despise more than anything else in my 10 years is cynicism".
He said there had been real progress in Sierra Leone where he sent peacekeeping troops during his first term of office.
The move made him a popular figure in the West African state, as it proved decisive in preventing rebels from taking over.
He was later made a paramount chief - a mark of respect in the country - during a ceremony in the village of Mahera.
Speaking after talks with the country's President Ahmad Tejan Kabbah and Liberia's President Ellen Johnson Sirleaf, Mr Blair said: "However ferocious the challenges are in this part of Africa it's better to intervene and try to make a difference than stay out and try to cope with the consequences at a later time."
Asked about criticism of his visit, Mr Blair said just a few years ago Sierra Leone had been in danger of being taken over by gangsters - while today it was approaching elections.
"I don't say that is perfection, but I say it's a darned sight better than it was before," he said.
"All I'm saying to cynics back home is if we care it might make a difference and making a difference is what politics should be about."
During his visit he saw a display by the new army and police force. British troops have led efforts to rebuild the national army since 2000.
Sierra Leone is expected to hold presidential elections in August - the first poll since UN peacekeepers left in 2005.
It is now stable but it remains desperately poor and high levels of corruption are a major problem.
Mr Blair inspected a guard of honour at Lungi airport
Many people would like to see donor countries like Britain put more pressure on the government of Sierra Leone to ensure aid reaches the people who need it.
Asked by local reporters about allegations of poor governance in Sierra Leone, Mr Blair admitted development was "painfully slow" but said he was sure President Kabbah would do everything he could to make the forthcoming elections free and fair.
The prime minister had said he hoped his tour would help to focus attention on Africa and climate change in the run-up to the G8 summit.
He is also calling for a strengthened African Union peacekeeping force, to intervene in the continent's conflicts, backed by a £25m reserve fund from the EU.
He added: "Yes it's Africa's responsibility for peacekeeping, but we in the West have a responsibility to fund it, to help to train the force and with logistics. If we do not do that, the impact is faced not just here but in the wider world."
He also apologised for not visiting Freetown - which is a helicopter trip away from Lungi airport - which left some residents of the capital disappointed.
He told a local radio station: "I'm really sorry I couldn't come to Freetown but I say to you, next time I come back I will certainly come to Freetown and other parts of the country.
"It's just been a little difficult in terms of time today."
On his last major tour before he steps down as prime minister at the end of June, Mr Blair has already held talks with Libyan leader Muammar Gaddafi.