We have placed this link here because Afghanistan is on the FCO ‘Don’t got to parts of’ list at the time of writing. We constantly monitor the FCO travel advice site and our advice is to check their advice yourself using the link above.

If you click on their Travel Advice by Country left hand link you'll see that the 'don't go to' list of countries is broken into four sections:
1. Where the FCO advise against all travel to the country
2. Where the FCO advise against all travel to parts of a country
3. Where the FCO advise against all but essential travel to a country
4. Where the FCO advise against all but essential travel to parts of a country.

So, the current advice relates only to parts of Afghanistan. You can check to see which particular regions of Afghanistan the FCO is advising against travel and holidays to, by clicking on their Afghanistan link on the Travel Advice by Country page.

Lonely Planet - Afghanistan
Large areas of Afghanistan remain highly insecure. NATO-led military operations are ongoing against the remnants of the Taliban and Al-Qaeda. Acts of violence, often targeting foreigners, continue to occur in Kabul.Visitors should maintain a very high level of security awareness, avoid demonstrations and political gatherings, avoid travelling alone and in the dark, and contact their consular representative for the latest information.Afghanistan is among the most heavily mined countries on earth. Extreme caution should be taken when venturing into areas that may be mined.

Afghanistan - Online
Afghanistan, (which literally means Land of the Afghan) is a mountainous land-locked country located in Central Asia. It has a history and culture that goes back over 5000 years. Throughout its long, splendid, and sometimes chaotic history, this area of the world has been known by various names. In ancient times, its inhabitants called the land Aryana. In the medieval era, it was called Khorasan, and in modern times, its people have decided to call it Afghanistan. The exact population of Afghanistan is unknown, however, it is estimated to be somewhere around 31 million.

Wiki Travel - Afghanistan
WARNING: Afghanistan is currently in a highly volatile state, and non-essential travel is discouraged.