美军增兵伊拉克的行动已经结束。一名高级美军将领的发言人证实，去年为加强治安派驻伊拉克的战斗部队已经结束任务，离开了伊拉克。不过根据五角大楼的数字，驻伊美军现在的人数比起去年增兵前要多出1万6千多人。

Students of mathematics will tell you there is a traditional approach called Old Math, and there are concepts known as New Math. But they probably don't know about something that falls into neither category. That is Pentagon Math.

Before the surge, there were about 132,000 U.S. troops in Iraq. Now the Pentagon says there are 148,000. That's a substantial increase, more than 12 percent. Pentagon Spokesman Bryan Whitman was asked to explain.

增兵前，驻伊美军有13万2千人。五角大楼现在说，驻伊美军有14万8千人，增长幅度高达百分之12以上。记者要求五角大楼发言人拜伦.惠特曼做出解释。

"We've always said that we know there are certain capabilities that the United States military is going to have to continue to provide until the Iraqis can establish their own organic ability to do those things - medical, logistics, maintenance, air support," he responded.

惠特曼说：“我们一直在说，美国军队将不得不继续向伊拉克人提供某些领域的帮助，如医疗、后勤、维修和空中支援，直到伊拉克人自己有能力来做这些事。”

So these are support troops, not combat troops, and the support troops are staying - or being replaced by fresh reinforcements - to provide the same capabilities to the increasingly active Iraqi Army and Police.

所以，这些是援助部队，不是作战部队。援助部队将留驻伊拉克，或有新派部队跟他们换防，向日益自立的伊拉克军队和警察提供同样的帮助。

Boosting Iraq's Security

The Iraqis have demonstrated considerable combat ability in several recent operations, including the expulsion of insurgent and militia forces from Basra and Mosul. But they still can not provide all their own logistics support, and they lack air power, the ability to do medical evacuations and other important capabilities.

伊拉克部队在最近的战斗中展示了相当可观的作战能力，包括把反叛分子和武装分子从巴士拉和摩苏尔赶出去。但是他们还不能为自己提供所有的后勤支援，也没有空中力量，而且缺乏医疗撤退和其他方面的重要能力。

Indeed, the increased need for support troops was predicted back in February by Lieutenant General Carter Ham, who was the chief of operations for the senior U.S. military staff, when he predicted that about 8,000 of the surge forces would stay after the surge combat troops left.

其实美国参谋长联席会议作战部部长卡特.汉姆中将早在2月就已经预料到对援助部队的更大需求。当时他预测说，当增援的作战部队离开后，他们中大约有8千人将会留在伊拉克。

"It also takes into account, as our forces look to transition from leading to partnering and then to over-watch, the need to retain some key enabling capabilities, to help the Iraqi forces with their capabilities," he explained, "such capabilities as command and control headquarters, logistics, aviation, detainee operations and the like."

汉姆将军说：“还要考虑的是，我们部队的位置从主导转化为夥伴，再转化为看守，我们需要保持一些关键的军力帮助伊拉克部队，比如指挥控制中心、后勤、航空和执行拘押行动的能力等等。”

In the end, the Pentagon says the extra support troops number about 10,000.

五角大楼最后说，额外的援助部队大约有1万人。

But there are 16,000 more U.S. troops in Iraq than before the surge. The Pentagon says some of the other 6,000 extra U.S. troops are in the process of taking over for departing troops, so the overall number should go down by a few thousand in the coming weeks. But that still leaves at least a couple of thousand troops not exactly accounted for.

但是比起增兵前，驻伊美军现在多出1万6千人。五角大楼说， 大约6千美军正准备接替将要离开伊拉克的部队，因此在未来几周里，驻伊美军总数将会下降几千人。不过，即使如此，还有至少两千士兵没被计算在内。

US Troop Withdrawal

The Pentagon spokesman, Bryan Whitman, says some may be leaving in the coming weeks, if their services are not needed by the Iraqis. In addition, he says U.S. commanders routinely request additional capabilities, such as bomb squads and intelligence units, which results in the deployment of small groups, or even individuals, which can add up over time.

五角大楼发言人惠特曼说，如果伊拉克不再需要，有些士兵也许会在未来几周之内离开伊拉克。不过他补充说，美军指挥官总是在要求增派人手，比如爆破队和侦察组，从而导致小分队、甚至个人不停地被派到伊拉克，所以人数慢慢地多了起来。

"The onesies and twosies become dozens, and the dozens become a few hundred, and a few hundred become a thousand sometimes," Whitman said. "It's just the way it does. Commanders have appetites for capabilities."

惠特曼说：“从一、两个人到几十人，从几十人到几百人，从几百人又增加到上千人，情况就是这样。指挥官们希望得到有各种能力的人。”

And he says commanders are always reluctant to give up capabilities once they have them.

惠特曼说，指挥官们一旦获得这些士兵，就不愿意让他们离开了。

"It's hard to give up capability. If you're a commander on the ground and you've got something that's working well, it's always a little bit hard to say, 'Well, we can do with less of this or less of that.' It's hard, I'm sure," he noted.

Combat Troops vs. Support Troops

The number crunching this week over the post-surge U.S. troop numbers in Iraq, raises a question - when Iraqi leaders call for the withdrawal of U.S. troops by 2010, are they talking about all the troops or just the combat troops? Or put another way, if the end of the surge left 16,000 troops behind, how many troops would a so-called complete U.S. withdrawal leave behind?

美军增兵行动结束后，驻伊美军到底有多少人，这在本周引起了关注。人们不禁提出一个问题：当伊拉克领导人呼吁美军2010年撤军时，他们说的是全部美军，还是只有战斗部队？

Experts say the Iraqi need for air support and other capabilities will not go away by 2010, and neither will the needs to protect American diplomats and reconstruction teams and to use high-end U.S. military capability to pursue any remaining hard-core terrorists and insurgents.

专家们说，到2010年，伊拉克还会需要空中支援与其他方面的支持。另外，美国外交官和重建队伍也需要受到保护，需要动用美军精锐部队来对付残余的强硬派恐怖分子和反叛分子。

The Democratic Party's presidential candidate, Barack Obama, also wants U.S. troops out of Iraq in 2010, but he is careful to specify that he's talking about combat troops, as he did during a news conference in Jordan on Tuesday, shortly after ending a visit to Iraq.

美国民主党候选人巴拉克.奥巴马也表示要在2010年把美军撤出伊拉克，不过他特别说明，他指的是作战部队，正如星期二他在访问伊拉克后在约旦举行的记者会上表示的那样。

"Once we redeploy our combat brigades, we're still going to retain a capability to protect our personnel, to target terrorists and to train Iraqi security forces, if there is political progress," Obama said.

“我们重新部署作战部队后，如果出现政治进展，我们还将保持军力，保护我们的工作人员，打击恐怖分子，并训练伊拉克保安部队。”

In Pentagon Math, even by a candidate who has pledged to end the war, if you deploy troops and then bring the troops home, you're still likely to have a substantial number of troops remaining. But no one is saying exactly how many will be, as we used to say in Old Math, 'left over.'

虽然奥巴马作为总统候选人誓言要结束伊拉克战争，但是根据五角大楼的计算方式，你在伊拉克部署完军队，然后再把军队撤回国，还会有一大批军队留在那里。