共和国总统乔·拜登预计将于周三宣布所有美国人部队将撤离从阿富汗到911袭击20周年时。

这是对当前形势大约2500名在阿富汗的美国军人发生了什么在过去的20年里。

美军在阿富汗

五角大楼官方表示，大约有2500名美国士兵在阿富汗服役，作为帮助阿富汗安全部队的咨询和援助任务的一部分。然而，美国官员承认，这一数字略高，因为美国反恐部队没有计入官方训练任务数量。

何塞·卡贝萨斯/法新社，通过盖蒂图片

美国陆军第一排科曼奇连的成员站在一个检查站

在阿富汗还有7000名北约士兵，作为阿富汗部队单独训练任务的一部分。他们在阿富汗的继续存在将由北约在预期的美军全部撤离后决定。

自2020年2月8日两名士兵在阿富汗东部的战斗中丧生以来，美国在阿富汗没有作战死亡。

在他们去世几周后，特朗普政府与塔利班达成了一项和平协议，确立了一个退出的最后期限只要塔利班停止攻击美国军队。

自那以后，塔利班一直没有袭击美国军队，但随着对阿富汗军队和平民的袭击增加，暴力水平也有所上升。

历史部队人数

美国在阿富汗的战争始于2001年10月7日，美国对基地组织目标进行空袭，以报复9.11袭击。塔利班政府给这个恐怖组织提供了一个安全的避难所，使其能够实施恐怖袭击。

少数美国特种作战部队协助北方联盟成功推翻了塔利班政府。

随着作战部队抵达阿富汗南部坎大哈附近的一个基地，到2001年底，美国的军事存在增加到近2300人。

帕特里克巴兹/法新社通过盖蒂图像，文件

美国海军陆战队与1/3海军陆战队查理公司巡逻通过丹麦陆军豹式2A5EK坦克

从历史上看，美国在阿富汗的军事任务平均在15000到25000人之间，直到2009年暴力水平升级。那一年，美国军队的人数增加了，甚至在巴拉克·奥巴马总统11月下令增兵3.3万人以遏制塔利班的胜利之前。

美军人数在2010年8月首次超过10万，并在接下来的一年保持在这一水平。

战争的代价

自2001年以来，共有2312名美国驻阿富汗军事人员死亡。这包括在最初的战斗任务(称为“持久自由行动”)中死亡的2218名服役人员，以及自2014年底被称为“自由行动哨兵”的训练任务创建以来死亡的94名服役人员。

随着2009年部队人数的增加，美国死亡人数也大幅增加，2009年至2012年期间，共有1534名美国人在阿富汗丧生。自2001年以来，有20，066名美国军人在阿富汗作战中受伤。

阿富汗战争中平民死亡人数是根据35，000至40，000人的估计得出的。布朗大学的一个项目估计有43，000名平民死亡，去年发布的一份联合国报告估计，在美国-塔利班协议后暴力激增之前，2001年至2019年估计有35，518名平民死亡。

根据五角大楼的数据，截至去年年底，美国在阿富汗的军事行动已经花费了8249亿美元——5785亿美元用于“持久自由行动”，2464亿美元用于“自由行动的哨兵”。

马苏德·侯赛因/法新社，通过盖蒂图像，文件

美国士兵在阿富汗霍斯特省易卜拉欣·凯尔村巡逻时就位

自由行动的哨兵每月平均支出为30亿美元。

引人注目的致命事件

阿富汗发生了几起引人注目的事件，造成大量美国人伤亡，包括塔利班袭击、直升机坠毁以及阿富汗部队对训练他们的美国部队进行的内部袭击。

美国在阿富汗伤亡最严重的一天是2011年8月6日，当时一架载有海军海豹突击队队员的CH-47奇努克直升机在阿富汗东部被一枚火箭榴弹击落。包括22名海军海豹突击队队员号在内的30名美国人在事故中丧生。

2005年6月28日，19名特种作战部队士兵在“红翼行动”中丧生，当时三名军人在一次伏击中丧生，另有16人在他们的直升机为帮助击退伏击而坠毁时丧生。

2008年7月13日，9名美国人和27名其他人在一次对美国观察哨的袭击中受伤，这次袭击被称为瓦纳特战役。

2009年10月3日，八名美国人和四名阿富汗人在战斗前哨基廷被杀，当时估计有200名塔利班战士袭击了阿富汗东部的偏远基地。

2009年12月30日，一名约旦双重间谍引诱七名中情局特工在查普曼前方作战基地的自杀式袭击中丧生。

2010年9月21日，一架黑鹰直升机在卡拉特坠毁，造成101空降师五名士兵、三名海军海豹突击队队员和一名海军特种作战支援技师死亡。

2011年4月27日，八名美国空军飞行员和一名美国承包商在喀布尔机场遇难。一名阿富汗空军飞行员在机场作战室的一次争论中变得愤怒，然后突然拔出枪开始射击。枪手在事件结束时受了致命伤。

2013年11月1日，在塔利班对萨勒诺营地(当时美国在该国的第三大基地)的协同袭击中，两名美国士兵丧生，数十人重伤。

As US troops prepare to pull out, a look at the war in Afghanistan by the numbers

PresidentJoe Bidenis expected to announce on Wednesday that all Americantroops will withdrawfromAfghanistanby the 20th anniversary of the Sept. 11 attacks.

Here is a look at thecurrent situationfor the approximately 2,500 U.S. service members in Afghanistan andwhat has transpiredover the last 20 years.

US Troops in Afghanistan

Officially the Pentagon says there are about 2,500 American troops serving in Afghanistan as part of an advise-and-assist mission to help Afghan security forces. However, U.S. officials have acknowledged the number is slightly higher as U.S. counterterrorism forces are not counted in the official training mission number.

There are an additional 7,000 NATO troops in Afghanistan as part of a separate training mission with Afghan forces. Their continued presence in Afghanistan will have to be decided upon by NATO in the wake of the expected full U.S. troop withdrawal.

There have been no American combat deaths in Afghanistan since Feb. 8, 2020 when two soldiers were killed in fighting in eastern Afghanistan.

Weeks after their deaths, the Trump administration reached a peace agreement with the Taliban that set adeadline for the withdrawalof all U.S. troops by May 1 of this year, as long as the Taliban stopped attacking U.S. forces.

The Taliban has refrained from attacking U.S. troops since then, but it has ramped up violence levels with increased attacks against Afghan forces and civilians.

Historic troop numbers

The U.S. war in Afghanistan began on Oct. 7, 2001, with American airstrikes against al-Qaida targets in retaliation for the Sept. 11 attacks. The Taliban government had given the terror group a safe haven from which it could carry out terror attacks.

A small number of U.S. special operations forces assisted the Northern Alliance as they successfully overthrew the Taliban government.

With the arrival of combat troops at a base near Kandahar in southern Afghanistan the U.S. military presence rose to almost 2,300 by the end of 2001.

Historically the U.S. military mission in Afghanistan averaged between 15,000 to 25,000 troops until 2009, when violence levels escalated. American troop levels increased that year, even before President Barack Obama’s surge of 33,000 troops ordered in November in an effort to stem Taliban victories.

The number of U.S. troops rose above 100,000 for the first in time in August 2010 and remained around that level for the next year.

The costs of war

A total of 2,312 U.S. military personnel in Afghanistan have died since 2001. That includes 2,218 service members who died during the original combat mission, known as Operation Enduring Freedom, and the 94 service members who have died since the creation of the training mission, known as Operation Freedom’s Sentinel, at the end of 2014.

With the increase in the number of troops in 2009, the number of American fatalities also increased significantly as 1,534 Americans died in Afghanistan between 2009 and 2012. There are 20,066 American service members who have been wounded in action in Afghanistan since 2001.

The number of civilian deaths in the war in Afghanistan are based on estimates that range from 35,000 to 40,000. A Brown University project estimated 43,000 civilian deaths and a United Nations report issued last year estimated that before the surge in violence following the U.S.-Taliban deal, an estimated 35,518 civilians were killed from 2001 to 2019.

Through the end of last year, according to the Pentagon, the U.S. military operations in Afghanistan have cost $824.9 billion -- $578.5 billion for Operation Enduring Freedom and $246.4 billion for Operation Freedom’s Sentinel.

The average monthly spending for Operation Freedom’s Sentinel has been $3 billion a month.

High-profile, deadly incidents

There have been several high-profile incidents in Afghanistan that resulted in significant numbers of American casualties, including Taliban attacks, helicopter crashes and insider attacks carried out by Afghan forces against the American troops that were training them.

The worst day for American casualties in Afghanistan was on Aug. 6, 2011, when a CH-47 Chinook helicopter carrying Navy SEALs was shot down by a rocket-propelled grenade over eastern Afghanistan. Thirty Americans, including 22 Navy SEALs, were killed in the crash.

On June 28, 2005, 19 Special Operations troops were killed during Operation Red Wings, when three service members were killed in an ambush and 16 others died when their helicopter went down in an effort to help fight off the ambush.

On July 13, 2008, nine Americans and 27 others were wounded in an attack on an American observation post that became known as the Battle of Wanat.

On Oct. 3, 2009, eight Americans and four Afghans were killed at Combat Outpost Keating when an estimated 200 Taliban fighters attacked the remote base in eastern Afghanistan.

On Dec. 30, 2009, a Jordanian double-agent lured seven CIA operatives to their deaths in a suicide attack on Forward Operating Base Chapman.

On Sept. 21, 2010, a Black Hawk helicopter crashed in Qalat, killing five soldiers of the 101st Airborne, three Navy SEALs and one Naval Special Warfare support technician.

On April 27, 2011 eight U.S. Air Force airmen and one American contractor were killed at the Kabul Airport. An Afghan Air Corps pilot became angry during an argument in the operations room at the airfield, then suddenly drew his gun and began shooting. The shooter was fatally wounded at the end of the incident.

On Nov. 1, 2013, two U.S. troops were killed and dozens more were seriously injured in a coordinated Taliban attack on Camp Salerno -- the third largest U.S. base in the country at the time.N