美国总统唐纳德·特朗普(Donald Trump)周二公布了开始建设一个复杂的新导弹防御盾这可以拦截来自太空的威胁，估计这项努力将耗资约1750亿美元，并在三年内投入使用。

　　“金色穹顶”项目将由太空部队将军迈克尔·格特林领导，呼应了罗纳德·里根总统失败的“星球大战”计划，该计划被批评为过于雄心勃勃，并从其他国家优先事项中抽走资金。白宫引用技术进步作为里根的一些设想现在成为可能的原因。

　　特朗普在宣布该计划时表示:“金色穹顶的这一设计将与我们现有的防御能力相结合，应该会在我的任期结束前全面投入使用。”“所以我们将在大约三年内完成。一旦完全建成，即使导弹从世界其他地方发射，即使是从太空发射，黄金穹顶也将有能力拦截导弹。”

　　特朗普开始呼吁美国建立类似于以色列的一年前，在目睹了以色列在那年春天伊朗的攻击中偏转了大约300枚导弹和无人驾驶飞机后，铁穹参加了竞选活动。军方官员当时说，他们没有表示需要这样一个全面的防御系统来保护美国，而批评人士指出，美国没有受到邻国加拿大和墨西哥的威胁，并且有两个大洋作为缓冲。

　　尽管如此，一些专家表示，提高国家抵御空中威胁能力的想法早就应该提出了。

　　导弹防御专家汤姆·卡拉科奇说，美国目前的系统主要侧重于击落来自朝鲜等流氓国家的洲际弹道导弹的能力。但他说，当涉及到无人机、巡航导弹和高超音速武器等其他威胁时，美国需要更好的保护。

　　“事实是，我们非常脆弱，”导弹防御项目主任、战略与国际研究中心国防和安全部高级研究员卡拉科奇说。

　　然而，一个问题是，美国在短短三年内可以发展多少能力，特别是考虑到特朗普宣布的发展天基拦截器网络的目标。

　　“这并不是说它不能比一些人想象的更快完成，但三年将推动其中一些事情，”卡拉科奇说。

　　在椭圆形办公室站在特朗普旁边的是将领导该项目的五角大楼太空行动副主任Guetlein和国防部长Pete Hegseth，他说该项目现在是可能的，因为自里根时代以来技术已经得到了改善。

　　“技术不在那里。现在是了，”海格塞斯这样评价里根的“星球大战”计划。“你一直在说，我们将保护国土免受巡航导弹、弹道导弹、高超音速导弹、无人机的攻击，无论它们是常规导弹还是核武器。”

　　在国会山，初步迹象显示，共和党人将支持参议院军事委员会主席、密西西比州参议员罗杰·威克(Roger Wicker)的努力，承诺在即将出台的支出法案中包括250亿美元的“首付款”。

　　然而，民主党人质疑过高的价格。该委员会的最高民主党参议员杰克·里德(Jack Reed)上周指出，白宫要求明年的预算约为1130亿美元，但没有概述该计划将实现的目标和时间的明确计划。

　　“在这一点上，这基本上是一个行贿基金，”罗德岛州民主党参议员里德说。

　　特朗普关于建设“最伟大的穹顶”的言论似乎源于竞选活动。在观看了以色列成功使用其铁穹之后，特朗普呼吁美国版本的呼吁在他的集会上受到了人群的欢呼，以至于共和党人在2024年选举之前将美国导弹防御系统的建设纳入了其党纲。今年1月，特朗普签署了一项行政命令，呼吁黑格斯实现这一目标。

　　特朗普在1月27日的命令中写道:“弹道导弹、高超音速导弹和巡航导弹以及其他先进空中攻击的威胁，仍然是美国面临的最具灾难性的威胁。”

　　自那以来，“国防部已经召集了最聪明的头脑和最优秀的技术人才，审查了一系列选项，这些选项考虑了当前的美国导弹防御技术和尖端创新，以迅速发展和建立一个可靠的保护伞来保护我们的国土，”五角大楼首席发言人兼海格塞斯的高级顾问肖恩·帕内尔本周早些时候表示，有报道称国防部一直在研究该提案。

　　仍然不清楚这个系统到底有多全面。还有一个问题是，这样一个雄心勃勃的项目是否会从其他重要项目中吸走资金。例如，美国空军正在用新的洲际弹道导弹替换400枚建于20世纪70年代的洲际弹道导弹。

　　赫格塞斯在一份声明中说:“今天存在一些美国在太空的技术，如天基传感器、空中和导弹防御，但组成金色圆顶建筑的所有系统都需要无缝集成。”"金色圆顶将分阶段部署，优先防御威胁最大的地方."

　　特朗普的计划似乎在国会成本估计的低端，但比想象的可能要快得多。本月早些时候，国会预算办公室估计，美国将需要在20年内花费1610亿至5420亿美元来开发和发射天基拦截器网络。

　　据CBO称，由于现有发射服务成本的下降，这些成本估计数低于几年前的水平。
 

Trump unveils plans for $175B 'Golden Dome' missile defense shield

　　President Donald Trump on Tuesday unveiled plans to begin building a sophisticated newmissile defense shieldthat could intercept threats from space, estimating the endeavor would cost some $175 billion and become operational in three years.

　　The project "Golden Dome," which will be led by Space Force Gen. Michael Guetlein, echoes President Ronald Reagan's failed "Star Wars" program, which was criticized for being overly ambitious and siphoning money away from other national priorities. The White House cited advancements in technology as a reason why some of Reagan's vision was now possible.

　　"This design for the Golden Dome will integrate with our existing defense capabilities and should be fully operational before the end of my term," Trump said in announcing the plan. "So we'll have it done in about three years. Once fully constructed, the Golden Dome will be capable of intercepting missiles even if they are launched from other sides of the world and even if they are launched from space."

　　Trump began calling for a U.S. missile defense shield similar toIsrael'sIron Dome a year ago on the campaign trail after watching Israel deflect some 300 missiles and drones amid Iran's attacks that spring. Military officials said at the time that they hadn't expressed a need for such a comprehensive shield to defend the U.S., while critics noted the U.S. wasn't under threat from its neighbors, Canada and Mexico, and is buffered by two oceans.

　　Still, some experts say the idea of improving the nation's ability to fend off aerial threats is long overdue.

　　Tom Karako, a missile defense expert, said the current U.S. system is focused mostly on the ability to shoot down intercontinental ballistic missiles from rogue states like North Korea. But the U.S. needs better protection when it comes to other threats like drones, cruise missiles and hypersonic weapons, he said.

　　“The truth is, we're pretty vulnerable,” said Karako, director of the Missile Defense Project and a senior fellow with the Defense and Security Department at the Center for Strategic and International Studies.

　　One question, though, is how much capability the U.S. can develop in just three years, particularly considering Trump's stated goal of developing a network of space-based interceptors.

　　“It's not to say that it can't be done sooner than perhaps some folks think, but three years is going to be pushing it for some of those things,” Karako said.

　　Standing beside Trump in the Oval Office was Guetlein, the Pentagon's vice chief of space operations who will lead the project, and Defense Secretary Pete Hegseth, who said the project was possible now because technology has improved since the Reagan days.

　　“The technology wasn't there. Now it is,” Hegseth said of Reagan’s "Star Wars" program. “And you're following through to say we will protect the homeland from cruise missiles, ballistic missiles, hypersonic missiles, drones, whether they're conventional or nuclear.”

　　On Capitol Hill, early indications were that Republicans would support the effort with Sen. Roger Wicker of Mississippi, chairman of the Senate Armed Services Committee, promising to include a $25 billion "down payment" in an upcoming spending bill.

　　Democrats, though, have questioned the steep price tag. Sen. Jack Reed, the top Democrat on the committee, noted last week the White House requested some $113 billion in its budget for next year without outlining a clear plan on what the program would achieve and when.

　　“That’s essentially a slush fund at this point," said Reed, D-Rhode Island.

　　Trump's talk of building "the greatest dome of them all" seemed to originate on the campaign trail. After watching Israel's successful use of its Iron Dome, Trump's calls for a U.S. version was met with cheers from crowds at his rallies so much that Republicans included the construction of a U.S. missile shield in its party platform ahead of the 2024 elections. In January, Trump signed an executive order calling on Hegseth to make it happen.

　　"The threat of attack by ballistic, hypersonic, and cruise missiles, and other advanced aerial attacks, remains the most catastrophic threat facing the United States," Trump wrote in the Jan. 27 order.

　　Since then, "the Defense Department has gathered the brightest minds and best technical talent available to review a full range of options that considers current U.S. missile defense technology and cutting-edge innovation to rapidly develop and field a dependable umbrella of protection for our homeland," Sean Parnell, chief Pentagon spokesman and Hegseth's senior adviser, said earlier this week amid reports the Defense Department has been working on the proposal.

　　Still unclear is exactly how comprehensive the system would be. Also in question is whether such an ambitious program might siphon away money from other vital programs. The Air Force, for example, is in the process of replacing 400 of its intercontinental ballistic missiles built in the 1970s with new ones.

　　“Some U.S. technology in space such as space-based sensors and air and missile defense exist today, but all of the systems comprising the Golden Dome architecture will need to be seamlessly integrated,” Hegseth said in a statement. “Golden Dome will be fielded in phases, prioritizing defense where the threat is greatest.”

　　Trump's plan appears to be on the lower end of congressional cost estimates, but dramatically sooner than thought possible. Earlier this month, the Congressional Budget Office estimated the U.S. would need to spend anywhere from $161 billion to $542 billion over 20 years to develop and launch a network of space-based interceptors.

　　According to the CBO, these cost estimates are lower than they would have been years ago because of a decline in the cost of available launch services.