Mrs Robinson said she expected to be criticised for her comments
A former UN High Commissioner for Human Rights, Mary Robinson, has told the BBC she was taken aback by the "terrible" conditions in Gaza on a recent visit.
Mrs Robinson said it was "almost unbelievable" that the world did not care about what she called "a shocking violation of so many human rights".
Israel tightened a blockade on Gaza after Hamas took control there in 2007.
On Tuesday, Egypt temporarily opened its Gaza border to allow students and people needing medical care to cross.
Mrs Robinson, a former president of Ireland, told the BBC she had been "taken aback with the terrible, trapped situation of the families" in the Gaza.
She said the situation had deteriorated since she last visited the Palestinian territory in 2000, and was far worse that in towns in the West Bank.
Women she spoke to said their farm lands had been bulldozed and their families were unable to find jobs or supplies.
"Their whole civilisation has been destroyed, I'm not exaggerating," said Mrs Robinson.
"It's almost unbelievable that the world doesn't care while this is happening."
Israel and Egypt have blockaded the overcrowded and impoverished Gaza Strip since Hamas violently seized control of the territory in June 2007.
Israel says the blockade, under which it has allowed little more than basic humanitarian aid into Gaza, is needed to isolate the militant group and stop it and other militants from firing rockets into Israel.
Israel came to a truce with Palestinian groups in June this year, but Mrs Robinson said this had had little effect on people's lives and "just brought a bitter taste in the mouth".
She said people in Gaza were the responsibility of Israel and suggested that ordinary Israelis did not understand the situation as they "couldn't possibly support it if they really did".
The former commissioner called on European countries and the rest of the world to do more to understand the "inhumane" conditions.
She said she expected that she would be criticised for her comments but that the issue had to be addressed.
"When I see 1.4 million trapped in a situation of collective punishment, without rights, I have to raise that, and I will go on raising it," she said.
On Tuesday, Egypt temporarily opened its Rafah border with Gaza to students and people seeking medical treatment.
The crossing has been closed for almost two-and-a-half years, but has occasionally been opened for humanitarian reasons.
Israel insists "normal business" cannot resume at Rafah until Hamas releases an Israeli soldier, Cpl Gilad Shalit, captured two years ago.
Earlier this year, hundreds of thousands of Gazans flooded across when the border was breached.
Egyptian officials said the crossing was likely to be open for three days, giving several thousand Gazans the chance to go into Egypt and bring supplies into Gaza.