????上周早些時(shí)候，達(dá)沃斯世界經(jīng)濟(jì)論壇（the World Economic Forum）一開(kāi)幕，就有人開(kāi)始議論紛紛：全球金融精英齊聚一堂，諸多國(guó)家元首及財(cái)政部長(zhǎng)紛紛亮相，美國(guó)代表團(tuán)成員的級(jí)別卻明顯較低。沒(méi)有財(cái)政部長(zhǎng)，沒(méi)有國(guó)務(wù)卿。當(dāng)然也沒(méi)有國(guó)家元首。

????其次是這樣的情況：奧巴馬總統(tǒng)在上周一發(fā)表的第二次就職演說(shuō)中，著重提到的是大量的國(guó)內(nèi)問(wèn)題，而對(duì)于是否打算在第二個(gè)任期內(nèi)在國(guó)際上發(fā)揮自己強(qiáng)有力的領(lǐng)導(dǎo)才能方面，卻沒(méi)有什么表示。約翰霍普金斯大學(xué)高級(jí)國(guó)際研究學(xué)院（Johns Hopkins University School of Advanced International Studies）院長(zhǎng)、前奧巴馬政府高級(jí)官員瓦利?納斯?fàn)柋г拐f(shuō)：當(dāng)美國(guó)內(nèi)部辯論占據(jù)主導(dǎo)地位時(shí)，“有些人就會(huì)想當(dāng)然地認(rèn)為可以暫停對(duì)國(guó)際事務(wù)的關(guān)注或參與?！?/p>

????將上述兩個(gè)情況放在一起考慮，世界經(jīng)濟(jì)論壇的與會(huì)者不由得提出這樣的問(wèn)題：奧巴馬的軍事干預(yù)政策曾被一位顧問(wèn)形容為“幕后領(lǐng)導(dǎo)”，現(xiàn)在他是在有意識(shí)地放棄美國(guó)在世界經(jīng)濟(jì)中占據(jù)的領(lǐng)導(dǎo)地位嗎？如果是這樣的話，是否有任何一個(gè)能力遠(yuǎn)遠(yuǎn)不及美國(guó)的國(guó)家來(lái)填補(bǔ)這個(gè)空缺呢？

????上周四早上，倫敦對(duì)此做出了回答——英國(guó)首相戴維?卡梅倫走上了講臺(tái)，嘗試扮演這個(gè)角色?？穫悇偺幚硗臧柤袄麃喌囊黄饘?dǎo)致至少37人死亡的恐怖襲擊事件。他在上周四早上的演講中宣布，我們正在“與兇殘的恐怖主義進(jìn)行一場(chǎng)長(zhǎng)期的斗爭(zhēng)”。

????不過(guò)，卡梅倫特別顯示出領(lǐng)導(dǎo)權(quán)威的是在經(jīng)濟(jì)方面。英國(guó)首相卡梅倫上周三宣布，計(jì)劃與歐盟就英國(guó)保留歐盟成員國(guó)地位的條件進(jìn)行談判，比如嘗試減少對(duì)企業(yè)的監(jiān)管約束，然后讓英國(guó)選民通過(guò)公投來(lái)決定他們是否仍然想繼續(xù)保留歐盟成員國(guó)的地位。許多歐洲領(lǐng)導(dǎo)人及一些英國(guó)企業(yè)老總對(duì)他的這番言論仍然感到震驚。

????不過(guò)，上周四卡梅倫還利用一個(gè)不同的身份——即作為今年八國(guó)集團(tuán)輪值主席的身份——大膽直言?？穫愋?，他將利用自己這個(gè)身份，“聯(lián)合全歐洲大陸積極促進(jìn)企業(yè)釋放活力?！彼赋觯?guó)已削減了企業(yè)所得稅稅率，減少了監(jiān)管約束，并且向發(fā)展中經(jīng)濟(jì)體派遣了龐大的經(jīng)貿(mào)代表團(tuán)，向他們傳遞了“英國(guó)重新提倡貿(mào)易開(kāi)放”的信號(hào)。

????他說(shuō)，現(xiàn)在他計(jì)劃著手解決企業(yè)逃稅和避稅問(wèn)題，推動(dòng)經(jīng)濟(jì)體系向更加公平，更具競(jìng)爭(zhēng)力的方向發(fā)展。 他說(shuō)：“如果一家企業(yè)不繳納應(yīng)該繳納的稅款，其他企業(yè)最終就等于是繳納了更多的稅款。一部分奸商對(duì)經(jīng)濟(jì)體系玩花招時(shí)，所有企業(yè)都會(huì)因他們的名譽(yù)受損而遭受不利的影響?！?/p>

????美國(guó)的表現(xiàn)與此形成了鮮明的對(duì)比，美國(guó)共和黨和民主黨議員（以及白宮）只是空口答應(yīng)了要對(duì)企業(yè)所得稅進(jìn)行改革——以此承諾會(huì)提高美國(guó)的國(guó)內(nèi)生產(chǎn)總值，并且把海外資金吸引到美國(guó)國(guó)內(nèi)用以本土投資。

????奧巴馬喜歡攻擊企業(yè)的避稅行為，這在競(jìng)選過(guò)程中發(fā)揮了很好的作用?？穫悇t在履行一個(gè)使命：點(diǎn)燃推動(dòng)經(jīng)濟(jì)增長(zhǎng)的火箭引擎。他大幅降低了英國(guó)的企業(yè)所得稅稅率，而現(xiàn)在才開(kāi)始打擊企業(yè)鉆空子的不法行為。

????The murmuring started as soon as the World Economic Forum opened here earlier this week: In this gathering of the globe's financial elites, featuring heads of state and finance ministers, the U.S. contingent was remarkably low level. No Treasury Secretary. No Secretary of State. And certainly no Head of State.

????Then there was this: President Obama's second inaugural address, given Monday, was heavy on liberal domestic issues, light on signs that he intended to exercise strong leadership abroad in his second term. "There is an assumption that you can push the pause button" on foreign affairs while internal debates dominate, complained Vali Nasr, dean of Johns Hopkins University School of Advanced International Studies and a former top Obama administration official.

????Put those two together, and WEF attendees were asking: Was Obama, whose military intervention policy was once described by an adviser as "leading from behind," consciously ceding the American position as economic world leader? And if so, was any other country remotely equipped to fill the void?

????On Thursday morning, the answer came in from London: British Prime Minister David Cameron stepped up to the podium to audition for that role. In his Thursday morning address, Cameron -- fresh from handling a terrorist attack in Algeria that left at least 37 dead -- declared that we are in a "long struggle against murderous terrorists."

????But it was on the economic front that Cameron especially showed muscle to charge ahead. European leaders, and some UK business chiefs, were still reeling from the Prime Minister's Wednesday announcement that he planned to renegotiate his country's terms of membership in the EU -- seeking to reduce regulation on business, for example -- and then let British voters decide if they still wanted to be part of the union.

????On Thursday, though, Cameron spoke out in a different role -- as president of this year's G-8. In that capacity, Cameron announced an "aggressive, pan-continental drive to unleash enterprise." Already, he noted, the UK has cut the corporate tax rates and reduced regulation, and sent huge trade delegations to growing economies with the message that "Britain is back open for business."

????Now, he said, he plans to tackle corporate tax evasion and avoidance, to make the system fairer and more competitive. "When one company doesn't pay the taxes they owe, then other companies end up paying more. When some cowboys play the system all businesses suffer the fall-out to their reputation," he said.

????Contrast that to Washington, where both Republican and Democratic lawmakers (and the White House) have given only lip service to corporate tax reform -- which holds out the promise of boosting GDP and bringing offshore capital back home for U.S. investment.

????Obama is fond of attacking corporations for tax avoidance; it plays well on the campaign trail. Cameron is on a mission to light the rocket engines under economic growth: He dramatically reduced his country's corporate tax rate -- and only now is going after the loopholes.