唐納德·特朗普正積極準(zhǔn)備對中國發(fā)動貿(mào)易戰(zhàn)：他在周四下午公布了對中國制造的數(shù)百種商品征收關(guān)稅的計劃。但最為關(guān)鍵的是，我們必須弄清楚中國向美國出口商品的收益流向了何方。

中國對美國的貿(mào)易盈余，除了以極低的利率為美國各行各業(yè)提供大量發(fā)展資本以外，大都購買了美國國債，用于支付美國政府規(guī)模龐大且日益膨脹的聯(lián)邦赤字。因此，美國極其依賴中國的低息貸款。美國不計后果的財政路線，因為最近的減稅和支出增加變得危機重重，而對中國的這種依賴正在令情況變得更加糟糕。

特朗普應(yīng)該知道：如果你要引爆與中國的貿(mào)易戰(zhàn)，請認(rèn)真考慮一下一旦中國開始拋棄美國國債，會有怎樣的后果。

要弄清楚為什么中國放棄美國國債是一個嚴(yán)重威脅，首先要了解美國在赤字和債務(wù)膨脹的情況下為什么能夠保持適度穩(wěn)定的增長速度。通常，美國財政部的巨額借款會導(dǎo)致利率大幅提高，因為聯(lián)邦政府要與急需資本的企業(yè)爭奪有限的國內(nèi)儲蓄。但美國卻一直維持極低的利率，因為憑借美國國債無與倫比的安全性以及私營部門股票和債務(wù)的豐厚回報率，美國吸引了創(chuàng)紀(jì)錄的外國儲蓄，可供政府使用。

而美國最大的外國債主以及政府瘋狂借貸的主要支持者，就是我們最大的貿(mào)易伙伴：中國。今天，中國持有約1.2萬億美元美國國債；如果中國對美國的債券失去興趣，美國經(jīng)濟將會遭到毀滅性的打擊。

美國難以承受的后果

實際上，無論貿(mào)易領(lǐng)域發(fā)生怎樣的摩擦，中國都已經(jīng)在逐步減少購買美國新發(fā)行的國債。盡管每年中國對美國的貿(mào)易順差一直穩(wěn)定在3,500億美元，但卻遠(yuǎn)低于幾年之前的最高水平。受到人民幣升值等因素的影響，中國作為出口國的實力有所減弱，已經(jīng)導(dǎo)致中國的外匯儲備規(guī)模大幅縮小。與此同時，美國政府預(yù)計本財年的財政赤字將從2017年的6,670億美元擴大到接近1萬億美元，如果維持當(dāng)前的支出和稅收政策，到2027年財政赤字預(yù)計將達(dá)到2.4萬億美元，美國的資金需求將迅速增長，但中國可以提供的資金將會大幅減少。簡單地說，美國的國債供應(yīng)會呈爆炸式增長，但隨著中國減少購買美國國債，外國需求卻很有可能較過去更加保守。

這種情況的影響已經(jīng)顯現(xiàn)，將會帶來一個美國無法承受的后果：利率飆升。當(dāng)然，由于美聯(lián)儲承諾將在短期內(nèi)連續(xù)加息，美國經(jīng)濟最近也開始復(fù)蘇，因此美國國債收益率一定會有所上漲。但國會預(yù)算辦公室（Congressional Budget Office）預(yù)測，至2027年年底，10年期國債的收益率只會從今天的約2.8%提高到3.7%。據(jù)盡責(zé)聯(lián)邦預(yù)算委員會（Committee for a Responsible Federal Budget）預(yù)測，即便國債收益率穩(wěn)定在這一區(qū)間，到2028年，美國國債利息將達(dá)到約1.1萬億美元。（相當(dāng)于未來十年社會保障預(yù)測支出的三分之二。）

考慮到利息的規(guī)模，“實際”收益率或通脹調(diào)整后收益率大幅上漲，其后果都將是災(zāi)難性的。（重要的是實際收益率而非名義收益率，因為美國財政部可以通過提高對高收入人群征稅，來補償通貨膨脹的適度增長。）實際收益率大幅上漲會導(dǎo)致“山姆大叔”和美國企業(yè)的借貸成本激增，并增加聯(lián)邦政府履行軍費開支、退休福利等義務(wù)的成本。

可以想象，特朗普與中國鬧翻，一定會引發(fā)最為極端的報復(fù)：中國突然停止購買美國國債。目前，在外國主權(quán)投資者持有的6萬億美元美國國債當(dāng)中，中國持有約1.2萬億美元，占20%；日本持有1.1萬億美元。如果舊債期滿后，中國停止購買新發(fā)行國債，美國主權(quán)債務(wù)的全球市場會大幅收縮，導(dǎo)致實際收益率突然上漲。

沉重的財政負(fù)擔(dān)

想象一下到2028年，美國10年期國債的收益率不是上漲到3.7%，而是4.8%。據(jù)《財富》雜志估計，聯(lián)邦債務(wù)總額將從預(yù)測的33萬億美元激增至36萬億美元，年利息支出將從1.1萬億美元增加到1.5萬億美元。這相當(dāng)于政府預(yù)測的美國最大的一筆福利支出 ——醫(yī)療保險支出的75%。而債務(wù)增加會進一步影響聯(lián)邦政府通過其他投資拉動經(jīng)濟增長的能力。

誠然，這并不是最可能出現(xiàn)的結(jié)果。穆迪分析（Moody’s Analytics）的首席經(jīng)濟學(xué)家馬克·扎蒂表示：“針對美國的關(guān)稅措施，中國更有可能采取的應(yīng)對措施是使人民幣貶值，或者對美國公司在中國開展業(yè)務(wù)設(shè)置更多障礙和阻力。”原因是收益率大幅上漲將會減損美國國債在中國龐大的外匯儲備中的價值。對于中國有利的一面是，這種變化也會抵消中國將到期美國國債換成人民幣給美元帶來的壓力，但即便美元小幅貶值也無法補償中國持有的固定收益證券價格的大幅下跌。

中國拋售美債的動機，不見得是出于憤怒或者報復(fù)。中國國家領(lǐng)導(dǎo)人可能認(rèn)為，貿(mào)易保護主義將妨礙美國的增長；一旦出現(xiàn)這種情況，對于美國無法處理債務(wù)和赤字的擔(dān)憂，可能促使全球投資者要求更高的美債收益率，來對沖持有美債所承擔(dān)的額外風(fēng)險。此時，中國和美國的其他海外債主，會在即將發(fā)生的收益率大幅上漲導(dǎo)致美國國債價格下跌之前退場。

貿(mào)易爭端依舊有升級的可能。但貿(mào)易戰(zhàn)的結(jié)果可能是中國受到沉重打擊，而美國卻陷入崩潰。如果中國選擇以放棄購買美國國債報復(fù)美國的關(guān)稅措施，中國就可以承受一場貿(mào)易戰(zhàn)。但其競爭對手美國因為沉迷于舉債早已虛弱不堪，一場貿(mào)易戰(zhàn)將令其陷入崩潰的邊緣。因此，特朗普在發(fā)動一場美國無法承受的貿(mào)易戰(zhàn)之前，應(yīng)該三思而后行。（財富中文網(wǎng)）

譯者：劉進龍/汪皓

Donald Trump is on the warpath against China over trade: On Thursday afternoon, he announced plans to impose a range of tariffs against hundreds of lines of Chinese-made goods. But it’s crucial to recognize where those dollars that China gains from selling us their goods are going.

The surplus flows right back into U.S. Treasuries, to fund our gigantic and ballooning federal deficits, in addition to providing tons of growth capital to stateside industries—all at bargain rates. Hence, the U.S. is extraordinarily dependent on cheap loans from China. And our reckless fiscal path, made far more treacherous by the recent tax cuts and spending hikes, is greatly worsening that dependence.

Message to Trump: While you’re battling with China, think hard about what happens if the Chinese start snubbing U.S. debt.

To see why that’s such a threat, it’s important to understand how the U.S. has been able to keep growing at a moderate but steady pace despite an explosion in deficits and debt. In most periods, the U.S. Treasury’s brobdingnagian borrowing would have pushed interest rates skywards as the federal government competed for the limited pool of domestic savings with capital-hungry businesses. But rates have remained extremely low because the U.S. has been able to tap a record pool of foreign savings, from nations lured by the matchless safety of U.S. government bonds and the excellent returns on our private sector equity and debt alike.

And our paramount foreign creditor, and leading enabler of our rampant borrowing, has been our biggest trading partner: China. Today, the Chinese own around $1.2 trillion in Treasuries; if they were to lose their appetite for our bonds, the economic repercussions could be catastrophic.

An outcome the U.S. can’t afford

China is already on the road to purchasing less of our newly issued debt, whatever happens on the trade front. Although its annual trade surplus with the U.S. has stabilized at around $350 billion, it’s well below its peak of a few years ago. And China’s waning power as an exporter, primarily due to the stronger yuan, has substantially lowered its holdings of foreign reserves. So just when the U.S. deficit is set to jump from $667 billion in 2017 to close to $1 trillion in this fiscal year, and an estimated $2.4 trillion by 2027 if current spending and tax policies continue, China will be meeting a lot less of our fast-growing need for funding. Put simply, the supply of Treasuries will explode, and foreign demand will likely prove more reserved than in the past, thanks in large part to shrinking purchases from China.

That scenario already threatens to cause precisely what the U.S. can’t afford: a spike in interest rates. Of course, yields are bound to rise somewhat because of the Federal Reserve’s pledge of serial short-term rate increases and a newly resurgent economy. But the Congressional Budget Office is forecasting that the 10-year Treasury yield will reach only 3.7% by the end of 2027, up from around 2.8% today. Even if yields stabilize in that range, interest on the debt would reach almost $1.1 trillion by 2028, according to a forecast from the Committee for a Responsible Federal Budget. (That’s the equivalent of two-thirds of projected spending for Social Security a decade hence.)

Given the weight of those carrying charges, any significant rise in “real,” or inflation-adjusted yields would prove disastrous. (What matter is real not nominal rates, since the Treasury would recoup moderate increases in inflation via higher tax collections on higher incomes.) A real-rate surge would increase borrowing costs for Uncle Sam and for businesses, and make it ever more expensive for the federal government to meet its obligations on everything from military spending to retirement benefits.

It’s conceivable that Trump’s feud with China will trigger the most extreme form of retaliation: A sudden pullback on purchases of U.S. debt. Today, the Chinese own around $1.2 trillion in Treasuries, 20% of the $6 trillion in federal debt held by foreign sovereign investors; the Japanese hold another $1.1 trillion. If the Chinese decline to roll their money into new Treasuries as the old ones mature, the worldwide market for U.S. sovereign debt would shrink, causing a sudden rise in real rates.

A heavy weight to carry

Imagine that by 2028, yields on the ten-year rise not to 3.7%, but an extra point, to 4.8%. By Fortune’s estimates, total federal debt would jump from a projected $33 trillion to $36 trillion, and annual interest expense would soar from $1.1 trillion to $1.5 trillion. That’s equal to 75% of projected spending on our biggest entitlement, Medicare. And that rising obligation would crowd out even further the government’s ability to invest in other spending that would bolster the economy.

Granted, that’s not the most likely outcome. “It’s more likely that China would respond to tariffs by devaluing the yuan, or by making it much more difficult for U.S. companies to do business in China,” says Mark Zandi, chief economist at Moody’s Analytics. The reason is that a sharp increase in rates would tank the value of the U.S. bonds in China’s giant portfolio of foreign reserves. On the plus side for China, it would also counteract pressure on the dollar from China’s trading the maturing Treasuries for local currency, but even a somewhat stronger dollar wouldn’t compensate for the drastic drop in the price of China’s holdings of fixed-income securities.

China’s motive for ditching U.S. debt doesn’t have to be anger or retaliation. Its leaders could reckon that protectionism will hobble U.S. growth; if that were to happen, fears that America can’t handle its debt and deficits might prompt investors worldwide to demand higher rates for the extra risk of holding Treasuries. Then, the Chinese and other overseas lenders would rush for the exits before a looming spike in yields pummels prices of U.S. bonds.

Still, it’s possible that the bad blood over trade could escalate. It’s a case where one nation—China—gets hit hard, and the other nation, the U.S., gets crushed. China can afford a fight where it retaliates against our tariffs by shunning our debt. But its opponent already totters, weakened by an addiction to debt. Trump should tread carefully before risking a fight that America can’t afford.