The Khyber Pass, described by Kipling as "a sword cut through the mountains" is a narrow gap through the formidable Hindu Kush range. It is too steep and cold to safely traverse during winter and late autumn.

The Hindu Kush could be nicknamed "Hindu killer" for two main reasons. First, the mountains are extremely dangerous, with high elevations and extreme climate preventing development or reliable transportation. Second, the Hindu Kush are the traditional "gateway to India" for invaders from the north and west, such as Alexander the Great and Genghis Khan.

The Khyber Pass is on Pakistan's border with Afghanistan.

According to the New York Times, more than 80 percent of American and ISAF supplies to Afghanistan flow through Pakistan, much of that through the Khyber Pass, one of the few clear gaps in the Hindu Kush. American and ISAF military leaders are working to find alternate routes, perhaps through Russia, Turkmenistan, Uzbekistan, or Tajikistan. Alternate supply routes would make the Khyber Pass less vulnerable to attacks from Afghan insurgents. As of late 2011, reliable alternate routes had not been established.

Kipling is actually quoting the Bible (Isaiah 40:6). The biblical author, as well as Kipling, compares human life to a blade of grass: short, and easily cut even shorter.

Peshawar and the Khyber Pass have been ravaged by the war in Afghanistan, making the phrase an apt one for the Khyber Paktunkhwa government to use.

Bullets continue to fly down the Khyber Pass: In late 2010, Pakistan temporarily closed its border to Afghanistan after an American helicopter crew accidentally shot and killed Pakistani soldiers in a tragic incident of "friendly fire." American and ISAF troops have killed dozens of insurgents in the province, and insurgents target local civilians as well as foreign military troops. Suicide bombers bomb mosques and marketplaces.