As the Prime Minister announced his withdrawal, senior British military officials warned that the country might fall into civil war.

British Prime Minister Boris Johnson confirmed that most British troops have left Afghanistan. This is nearly 20 years after the British and other Western countries sent troops into Afghanistan to conduct what they call the “war on terror.”

Johnson emphasized on Thursday that the threat posed by al-Qaeda to the UK has greatly diminished, but he avoided questions about whether his country and its NATO allies rushed out of the country might undermine nearly two decades of work or make Afghanistan vulnerable. The Taliban have made rapid progress in many parts of the north.

The prime minister refused to disclose the details of the withdrawal on security grounds.

But he stated that “all British troops assigned to NATO’s Afghanistan mission are now returning home”, adding that “most of our personnel have already left.”

“We must be realistic about our ability to influence the course of events alone. It takes the joint efforts of many countries, including Afghanistan’s neighbors, to help the Afghan people build their own future,” Johnson said.

“However, due to the bravery and sacrifice of the armed forces of the United Kingdom and many other countries, the threat that initially brought us to Afghanistan has been greatly reduced.”

He said that Britain remains committed to helping Afghanistan achieve a peaceful settlement through diplomacy.

“We will not go away. We will leave the embassy in Kabul, and we will continue to work with our friends and allies, especially our friends in Pakistan, to work towards a settlement,” Johnson said.

During the British deployment, a total of 457 British soldiers died in Afghanistan. Compared with the British participation in the Iraq War, the death rate was much higher.

The last batch of British combat troops left Afghanistan in October 2014, but as part of NATO’s mission to train Afghan troops, about 700 people still remain in Afghanistan.

The British Ministry of Defence stated that the withdrawal of the last batch of troops will be “completed within a few months.”

When Johnson announced the withdrawal, the head of the British Armed Forces warned that as the United States and other foreign troops withdrew, Afghanistan might go to civil war.

In comments made after Johnson announced the news, Chief of Defense Staff Nick Carter stated that it is “reasonable” for the country to collapse without international troops.

Afghanistan may have a situation similar to the country’s civil war in the 1990s. “In this case, you will see a culture of warlordism. You may see some important institutions such as security forces split along ethnic or tribal boundaries.” Carter said.

“In that case, I guess the Taliban will control part of this country. But, of course, they will not control the entire country.”

The US military announced on Tuesday that 90% of US troops and equipment have left the country, and the drawdown will be completed by the end of August.

Last week, US officials evacuated the Bagram Air Force Base, the country’s largest airport, at the center of the war to clear the Taliban and hunt down the perpetrators of Al Qaeda that attacked the United States on 9/11.

In recent weeks, most European troops have also quietly withdrawn.

British Defense Minister Ben Wallace once said that once the United States announced its decision to leave, Britain would be in a “very difficult position” to continue its mission.