What general problem is behind the trend to fencing &wall-bldg of international land borders around the world?

For example, fences & walls are being built around the world in places like the border between Bangladesh and India by India; the border betw the Palestinian West Bank and Jewish Israel by Israel, and the southern border betw the US and Mexico by the US.

Unequal distribution of wealth, income and access to opportunity.

Asker's Rating Comment is sensible than the intention of the Question and 'Additional Details' provided. In any case, it's good to know that he acknowledged that "I challenge anyone to prove that fences and walls have achieved anywhere their purpose". Good Luck to the insecure fence-builders! http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWzS_UzMDrtfjZFd4&s=comm&date=2007-06-29+18%3A06%3A38&.crumb=

I am wondering what logic lends anyone to think that fences have no effect, or even facilitate unwanted indviduals from going somewhere they are not wanted. So fences don't impede illegal immigrants? http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjW7WDXb8vBZME2D&s=comm&date=2007-06-30+06%3A54%3A16&.crumb=

Your logic in another arena makes as much sense.... police don't elimate crime so let's do without law enforcment.

Wake up you sleepy heads! Hungry, minimally educated Mexicans aren't the only potential immigrants that the US could be absorbing. http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjW7WDXb8vBZME2D&s=comm&date=2007-06-30+06%3A58%3A57&.crumb=

Why do people want 8 million almost literates instead of 8 million tech workers with graduate degrees paid for by another country?

Is it because we are afraid of our place in the US food chain? Now who's insecure? http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjW7WDXb8vBZME2D&s=comm&date=2007-06-30+07%3A05%3A48&.crumb=

Bizsmithy, The Q is more general than you are willing to recognize. Also history is replete with walls and fences that did not achieve their purpose. eg Great Wall of China, Hadrian's Wall in northern England, The Berlin Wall, The Maginot Line between Germany and France. http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjK_UjPYy_Y.ECEb&s=comm&date=2007-07-01+08%3A35%3A10&.crumb=

Of course fences and walls are physical barriers to movement, but the real purpose behind their construction, why they were built, is the issue here. http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjK_UjPYy_Y.ECEb&s=comm&date=2007-07-01+08%3A35%3A32&.crumb=

Point taken, with two conditions:

1) Walls are only meant as impedements, as the walls listed above illustrate. Hadrian's wall, the Maginot line and I believe the Great Wall were all part of a larger constellation of deterrent actions which included war making retaliatory capabilities. http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjW7WDXb8vBZME2D&s=comm&date=2007-07-01+20%3A15%3A02&.crumb=

2) Not specifying the interval with which to judge a "wall" as successful gives the probability of success an infinite denominator. All things are failures over the infinite term. http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjW7WDXb8vBZME2D&s=comm&date=2007-07-01+20%3A23%3A14&.crumb=

The real test is whether they function long enough to justify their cost. I'm not sure that any of the wall examples above fail this test, even the Maginot Line. http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjW7WDXb8vBZME2D&s=comm&date=2007-07-01+20%3A24%3A07&.crumb=

I wish, esteemed questioner (smarttrollkikker), that you were receptive to allowing folks to add you to contacts. I understand why you do not.

Peace and best regards.. http://answers.yahoo.com/question/accuse_write?qid=20070626061039AAMzNVE&kid=NbUvWjW7WDXb8vBZME2D&s=comm&date=2007-07-01+20%3A28%3A48&.crumb=

"Good fences make good neighbors." That was either Mark Twain or Will Rogers. A fence demarks that this is mine and that is yours, making it easier for me to declare war on you if you cross this line. Fences have been used throught out history for protection, i.e. Great Wall of China.

Fences simply reinforce national boundaries when other nations don't respect the sovereignty of a neighbor. It's largely a symbolic show of the resolve and will of the people whose nation is being over-run by some perceived, unwelcome intruders.

The need for fences comes from increasing disparities along the dimension of developed pragmatic institutions in one nation and feudal confederacies of either corruption and/or superstitious histrionics in another.

Putting up of fence by India's unilateral decision on common borders between India and Bangladesh is more a political gimmick then to prevent Bangladeshis crossing over into India, which is farthest from the truth.

It is true that many people go to India mostly for visiting their families (mostly Hindus), business, better medical treatment, and negligible few for better prospect. India's print and electronic media would drum-up their leaderships' claim that Bangladeshis are standing 'on your marks - get set - ready - go' mode to jump into India, the way the Mexican would to get entry into U.S. This is outright faulty assumption. Indian leaders want to pressurize Bangladeshi governments by lodging one after another psychological wars, and border fencing is one of such wars.

I got the following from Internet search, From Wikipedia:

India was Bangladesh's key ally in the Bangladeshi Independence War of 1971 and even after the war provided military and reconstruction aide to the country. Throughout the years, relations between both countries continue fluctuating as ongoing border disputes and insurgency plague both nations. Bangladesh claims that India feels too comfortable in playing the role of "Big Brother" to smaller, weaker nations and India accuses Bangladesh over harboring Indian separatists hiding in Bangladesh. Nevertheless, recent peace agreements and strategic economic cooperatives have somewhat eased tensions.

[Edit]: As per the Additional Data and Link provider by the Asker, I would maintain the fact that the fencing of Bangladesh was more to do with punishing the then 'errant' rulers, though democratically elected in Bangladesh, who foolishly wanted to have independent foreign policy, instead of towing India like its favorite leader in Bangladesh Sk. Hasina of Awami League. We do not want confrontation with a country like India and with today's statement by visiting Indian Foreign Secretary Mr. Shiv Sankar Menon we can see ray of light in the improvement of relationship between this two neighborly countries.

RE: http://news.yahoo.com/s/ap/bangladesh_fenced_in;_ylt=Ah.fSB_Buypua36_f6T.GogDW7oF

In the United States, the decision to fence 700 miles of the Mexican border triggered months of political debate ranging across issues from immigration reform to the environmental impact. When Israel announced it would build a 425-mile barrier around the West Bank, an international outcry erupted.

But there has been barely a ripple over India's far larger project, launched in earnest in 2000 amid growing fears in New Delhi about illegal immigration and cross-border terrorism.

The Bangladesh government made a few complaints â€" the fence felt like an insult, as if their country was a plague that needed to be quarantined â€" but soon gave up.

India has become enamored with fences in recent years.

First it started closing off much of its border with Pakistan, trying to stop incursions by Muslim extremists. Then it turned to its other Muslim neighbor, Bangladesh, and has been building the fence intermittently ever since.

There's no clear completion date for the $1.2 billion project, which when finished will nearly encircle Bangladesh â€" leaving open only its seacoast and its border of about 200 miles with Myanmar.