On Copacabana Beach in Rio de Janeiro, a line of 26 black crosses stand in the sand, with the Stars and Stripes behind them and a pot of flowers alongside.

They are the tribute of the group Rio de Paz -- River of Peace -- to the victims at Sandy Hook Elementary School, from a group that knows all too well what tragedies gun violence can inflict on society.

Brazil, Norway, Britain, France and Australia are among many countries that have seen terrible episodes of gun violence in recent years.

But alongside the many expressions of sympathy and condolences that have poured into Newtown, Connecticut, from around the world, there is also a sense of bewilderment that such tragedies happen on an almost routine basis in America.

"Routine" may seem an exaggerated or callous description, but it was President Barack Obama who said at an interfaith service Sunday night in Newtown: "We can't accept events like this as routine."

Even so, commentaries from abroad often include a sense of resignation that much can or will be done to prevent such atrocities in the future.

John Cassidy, who is British and blogs for The New Yorker, writes of driving to his hometown of Leeds in northern England, as he heard the news of the killings at Sandy Hook.

"Nowhere have mass shootings been as prevalent as the United States, and nowhere has the policy reaction been so pathetic," he wrote this weekend.

Brian Masters, writing in the UK's Daily Telegraph, agreed.

"No American politician will have the nerve to propose the only cure to this repetitive insanity, which would be a sensible, mature and responsible attitude towards the ownership and use of guns," he predicted.

In the Israeli newspaper Yedioth Ahronoth, commentator Tzipi Shmilovitz was more brutal.

"America is not ready to talk about how it is easier to get a handgun than it is to see a doctor, not ready to speak about the video games that have extreme violence. It is just willing to sweep up everything under the carpet of tears."

And over at Haaretz, one of Israel's leading commentators, Chemi Shalev, lamented a "combustible mix of angry American young men, often disturbed and usually white, spurred on by the pervasive and always growing presence of limitless violence in popular American culture, together with the easy-access, open market of guns and ammo, which together produce these shooting slaughters with such sickening regularity. ...

"And if you pour in the often gruesome violence so rampant in the computer and video games that so many American boys are weaned on and addicted to, it should come as no surprise, perhaps, that not only are the most evil and inhuman of mass murders possible, they may soon become commonplace," he added.

Such observations are not new. Five years ago Chris Lockwood, U.S. editor of The Economist wrote in the Los Angeles Times: "We might be a little surprised that a country with all the ingenuity and energy that America has seems simply to throw up its hands when it comes to guns, and in effect declares that the homicide rate and regular appalling school massacres, are insolvable problems."

Obama has now suggested otherwise -- broadening his existing support for a ban on assault weapons.

"We can't tolerate this anymore; these tragedies must end," he said Sunday.

"We will be told that the causes are complex and that is true. No single law, no set of laws can eliminate evil and prevent acts of violence, but that can't be an excuse for inaction," he continued.

Commentators and academics from other countries who have looked at this "inaction" in America often raise the following points.

The polarization in U.S. politics means that on the really difficult issues, paralysis is more likely than progress. The power of lobbying interests -- and in the case of guns that means the National Rifle Association -- contributes to that paralysis, they say.

They also assert that the U.S. Constitution and its political culture protects individual liberty -- or license -- to a much greater degree than is the case almost anywhere else. That includes allowing the ownership of powerful firearms capable of killing dozens within a minute.

Sixteen years ago, both Australia and the United Kingdom saw gun rampages similar to those at Virginia Tech, the Sikh temple in Wisconsin, the theater in Aurora, Colorado, and Sandy Hook.

In the town of Dunblane, Scotland, 16 children and one adult were shot dead at an elementary school in 1996. The gunman then shot himself. The atrocity led to revisions to the Firearms Act that in effect banned the possession of handguns in Britain.

Jack Straw, the minister who pushed the legislation through Parliament, said after the Sandy Hook killings that he would "not put money" on U.S. laws changing.

In a BBC interview, Straw added: "I think sensible people want it to happen, but the National Rifle Association, which is this extraordinary gun lobby and gun manufacturers' lobby, controls politics in a number of states."