圆仍在走强，日本对此或许也没有多少办法。
周 三，美元兑日圆跌至一美元兑85.32日圆，为八个月以前、2009年11月27日触及84.82以来的最低水平。如果继续跌破84.82，那么美元对日 圆就贬值到15年以来的最低，并逼近1995年4月达到的二战以来最低水平79.75日圆。周三纽约市场午盘，美元兑日圆报86.24。
日 本财务大臣野田佳彦(Yoshihiko Noda)周三在这个问题上提高声调，他说，日圆当前的走势“有些单边”。他还承诺更加密切地监测日圆汇率的变动，但拒绝透露是否会采取任何具体措施，其 言辞也基本没有起到削弱日圆的作用。如果政府采取削弱日圆的干预措施，那么它就需要抗衡一些非常大的力量：美元全线疲软，国际协调缺位，中国在日圆市场中 的作用越来越大。
日圆的升值是各种力量交织在一起而推动的。有报道称，美联储(Federal Reserve)可能会加强实施量化放松政策，以遏制美国经济放缓，受此影响，美国利率下降到了接近纪录低位的水平，使美日之间的利差收窄至多年以来最 小，这样投资者就没有多少动力抛出日圆而买进美元。
与此同时，中国今年以来一直在快速积累日圆。它拥有价值2.5万亿美元的外汇储备，是 世界最大的外汇市场参与者。据日本政府说，今年头五个月，中国一共积累了1.27万亿日圆，超过前几年的日圆购买量。中国只要把1%的资产变为日圆，这种 购买量就相当于日本的月度经常项目顺差，而经常项目顺差本身就是日圆长期强势背后的一个重要因素。
中国购买日圆刺激民间投资者跟进，提高了日本国债的需求。
野村证券(Nomura)驻新加坡外汇策略全球负责人福林特(Simon Flint)说，中国和其他投资者买进日圆比较容易，因为全球投资者已经多年避开日圆，意味着它们的投资组合里日圆很少。他说，毕竟所有人还有中国持有的日圆敞口都很低。
强 势日圆可能会对日本不温不火的经济复苏形成挑战，因为本币汇率高企会让其出口产品在国际市场上变得更加昂贵，而出口又是日本经济增长的一个关键推动因素。 美元兑日圆现在已经接近85的关口，一些分析人士和一些政府官员相信，如果跌破这个关口的话，政府将不得不采取某种措施削弱日圆。瑞穗实业银行 (Mizuho Corporate Bank)外汇部门高级副总裁Yuichiro Harada说，市场人士现在都在更加紧密地关注日本央行采取进一步放松措施的可能性。
这样的措施可能会以压低日本较长期利率为部分目的。降低利率，往往会给本币施加下行压力，但日圆是否会大幅走低还不清楚，因为美国的利率预计也会保持在低水平。日本曾在去年12月份尝试过一种类似的战术，对日圆的强势只产生了有限的影响。
日本的长期利率已经下跌。周三，日本基准10年期国债的收益率下降0.04个百分点至0.995%，七年以来第一次跌破了1%。
另外一种战术则是通过卖出日圆、买进美元来直接干预外汇市场。日本从2004年以来就一直没有采取过这种措施。
如今要干预市场可能会很困难，因为世界发达经济体已承诺要让市场力量来决定汇率水平。另外，如果要让汇率干预在更长时期内有效，通常需要进行国际协调。
从 外交的角度来看，日本可能也难以采取干预措施。东京曾支持美国敦促中国让其受到严重操控的汇率政策实现自由化，如果回过头来又干预市场、削弱日圆，那么就 有违应当让市场来决定汇率水平的主张。与此同时，最近美元的疲态对美国经济有利，它使美国出口商品在国际市场上更加便宜，有助于美国总统奥巴马 (Barack Obama)在2015年之前实现出口翻番的目标。巴克莱资本公司(Barclays Capital)日本固定收益策略负责人莫里塔(Chotaro Morita)说，出于这个原因，日本政府认为他们不能在没有得到美国同意的情况下进行干预。
大和证券(Daiwa Securities)社长铃木茂晴(Shigeharu Suzuki)说，就算日本政府努力采取什么措施，其效果也会相当有限。他把强势日圆称为大和证券的一件“头疼事”，和一种“困难、不利的因素”，因为它 往往会抑制日本投资者对该公司所出售海外投资产品的需求。他认为美元兑日圆的“合理”水平是90到100。
实施干预的话，就要同汇率市场上一些非常强大的趋势相抗衡。一个是美元的整体弱势。跟踪美元兑一揽子贸易加权货币汇率的ICE美元指数，过去一个月下降了大约5%。
过去一个月全球投资者都在返回高风险资产，但未能改变日圆对美元的强势。而在最近的一般情况下，当投资者把钱投进股票等高风险资产时，日圆往往是要下跌的。
衡量全世界公司的道琼斯全球指数(Global Dow Index)在过去一个月大约上涨了12%，而日圆也升值了，同一时期美元对日圆下跌了大约3%。
出口反弹提高了日本的经常项目顺差。截至3月31日的一年里，日本经常项目顺差同比增加27.9%，给日圆带来了上行压力。
The yen keeps getting stronger, and there might not be much Japan can do about it.
The dollar touched an eight-month low against the yen on Wednesday, at 85.32 yen per dollar. It was the U.S. currency's lowest level since Nov. 27, when it hit 84.82 yen. A breach below that mark would take the dollar to its weakest point against the yen in 15 years and bring into view the post-World War II low of 79.75 yen, reached in April 1995. Wednesday afternoon in New York, the dollar was at 86.24 yen.
Finance Minister Yoshihiko Noda stepped up his rhetoric on the issue Wednesday, saying the yen's 'current movement is a little one-sided.' And he promised to 'monitor' yen exchange rates 'more closely.' He declined to say whether he would direct any specific actions, and his words did little to weaken the currency. Any government intervention to weaken the yen would involve fighting very large forces: a broadly weak dollar, a lack of international coordination and China's growing role in the yen market.
Fueling the yen's rise has been a confluence of factors. Reports that the U.S. Federal Reserve might increase its quantitative-easing program to fight off a slowdown in the U.S. economy has sunk U.S. interest rates to near record lows. That has pushed the difference between U.S. and Japanese rates to the smallest level in years, giving little incentive for investors to prefer dollars over yen.
Meanwhile, China has been rapidly accumulating yen this year. The world's largest foreign-currency player -- China has $2.5 trillion worth of reserves -- had accumulated 1.27 trillion yen this year through May, according to the Japanese government, dwarfing its purchases in previous years. If the currency superpower were to shift only 1% of its assets into yen, the buying would be equivalent to Japan's monthly current-account surplus, itself a major factor behind the yen's long-term strength.
China's purchases of yen have prompted private investors to follow suit, driving up demand for Japanese bonds.
Simon Flint, global head of foreign-exchange strategy at Nomura in Singapore, says it has been easy for China and other investors to pile into yen because global investors have shied away from the currency for years, meaning they have little in their portfolios. 'The world and his dog and China are all underweight Japan, anyway,' he says.
The strong yen could challenge Japan's tepid economic recovery because a pricey currency makes the country's exports -- a key driver of its growth -- more expensive on the global market. The dollar is now close to the key threshold of 85 yen, a point below which some analysts and some government officials believe the government will be forced to act in a way aimed at weakening the yen. 'People in the market are now looking more closely at the possibility that the Bank of Japan could take further easing measures,' said Yuichiro Harada, a senior vice president in Mizuho Corporate Bank's foreign-exchange division.
Such steps could in part be aimed at driving down longer-term Japanese interest rates; lowering interest rates tends to put downward pressure on a currency. It isn't clear, however, that the Japanese currency would weaken much, because U.S. interest rates are expected to remain low, too. A similar tactic was tried in December and had only a limited effect on the yen's strength.
Long-term rates have already dropped in Japan. On Wednesday, the yield on Japan's benchmark 10-year government bond fell below 1% for the first time in seven years, ending down 0.04 percentage point at 0.995%.
Another tactic would be to directly intervene in currency markets by selling yen and buying dollars. That is something Japan hasn't done since 2004.
Market intervention could be difficult this time around because the world's developed economies have been committed to allowing market forces to direct currency levels, and it usually takes international coordination to make currency intervention successful over the longer term.
Japan could find it difficult to intervene from a diplomatic standpoint. Tokyo has supported the U.S. efforts to get China to liberalize its heavy-handed currency policy. Turning around and intervening in markets to weaken the yen would go against the argument that markets should be allowed to set currency levels. The U.S. economy, meanwhile, benefits from the recently weaker dollar, which makes the country's exports cheaper and helps in President Barack Obama's goal of doubling exports by 2015. For this reason, 'the Japanese government thinks they can't conduct intervention without the approval of the U.S.,' says Chotaro Morita, head of Japan fixed-income strategy research at Barclays Capital.
'Even if the Japanese government tries to do something, the effect would be quite limited,' says Shigeharu Suzuki, chief executive of Daiwa Securities. He calls the strong yen 'a headache' and a 'tough, negative factor' for Daiwa because it tends to damp demand for overseas investment products the firm sells to Japanese investors. He thinks the dollar in the range of 90 yen to 100 yen would be 'reasonable.'
An intervention would involve fighting very strong currency trends. One is broad dollar weakness. The ICE Dollar Index, which tracks the dollar against a trade-weighted basket of currencies, is down about 5% over the past month.
The yen has stayed strong against the dollar even as investors globally have moved back into riskier assets over the past month. That runs contrary to the recent pattern in which the yen had tended to decline as investors put money into riskier assets such as stocks.
The Global Dow Index, which measures companies around the world, is up about 12% over the past month. Meanwhile, the yen has strengthened, with the dollar dropping about 3% in that period against its Japanese counterpart.
A rebound in exports has increased Japan's current-account surplus, pushing it up 27.9% in the year ended March 31 from the previous year. That puts pressure on the yen to rise.