KABUL, Afghanistan -- More than a century ago, fearing that his country might be swallowed up in the Great Game rivalry between the British empire to the east and the Russian army to the north, an Afghan king made a radical decision: He banned railroads.

That edict effectively kept out foreign troops for a number of years. But it also left the Afghan economy, once a wealthy crossroads of the ancient Silk Road trading routes, largely cut off from the world at a time when trains were the engines of development.

Now, Afghanistan has just opened its first major railroad and is planning a half dozen more. The government is also inviting other countries to build tracks, part of plans for a "New Silk Route" that the U.S. hopes will help stabilize the region by promoting trading links.

China, Iran, Pakistan and India all have government or corporate plans for separate railroad projects across Afghanistan. Turkmenistan is completing its own plans for another line. And Uzbekistan has already built the first major rail link, a 47-mile line from the border town of Hairatan to Mazar-i-Sharif in Afghanistan's north.

One reason so many countries are helping Afghanistan belatedly join the rail age: They need trains if their companies hope to export the country's vast, untapped mineral wealth, estimated by U.S. surveys at nearly $1 trillion.

Both the railway projects and the prospects for future mining wealth will depend largely on whether the country can keep violence from escalating once the international military force withdraws most of its troops by the end of 2014. For investors, it's a question of whether the increased commerce is worth the risk and effort.

Competing for contracts to mine deposits of copper, gold, iron and lithium is Afghanistan's modern Great Game, and one of the prices the government is extracting from eager companies is a promise to develop the railroads necessary to carry the heavy cargo.

For now, plans for Afghanistan's railroads are progressing bit by bit. As part of its agreement to develop a massive copper mine in Aynak, the China Metallurgical Group Corporation (MCC) is being asked to build a 575-mile railway from the mine southeast of Kabul.

The Afghan government is also negotiating with the Indian-led consortium that won the contract for the equally huge iron deposits at Tajigak in central Afghanistan for the companies to fund a 560-mile railroad -- likely through Iran -- to bring out the heavy ore.

The story of how Afghanistan never got a major railroad pivots around Abdur Rahman Khan, the emir who ruled Afghanistan from 1880 to 1901. During his reign, Afghanistan was sandwiched between the British colonial rulers of India, which then encompassed modern-day Pakistan, and the Russian empire that extended into Caucasus areas of Central Asia.

Both sides were engaged in what was known as the Great Game to control the region. They were racing to build railroads in areas under their control as a way of quickly moving troops. By the 1880s, both the British and the Russians had built tracks that went right up to Afghanistan's border.

Rahman Khan responded with a decree that no railroad would be allowed to enter Afghan territory, reasoning that without them, it would be difficult for invading troops to cross the mountainous frontier, said Andrew Grantham, an editor for Railway Gazette who runs a website chronicling the history of the country's failed railroad projects.