France voiced concerns over the artificially low price of gold in 1968 and called for returns to the former gold standard. Meanwhile, excess dollars flowed into international markets as the United States expanded its money supply to accommodate the costs of its military campaign in the Vietnam War. Its gold reserves were assaulted by speculative investors following its first current account deficit since the 19th century. In August 1971, President Richard Nixon suspended the exchange of U.S. dollars for gold as part of the Nixon Shock. The closure of the gold window effectively shifted the adjustment burdens of a devalued dollar to other nations. Speculative traders chased other currencies and began selling dollars in anticipation of these currencies being revalued against the dollar. These influxes of capital presented difficulties to foreign central banks, which then faced choosing among inflationary money supplies, largely ineffective capital controls, or floating exchange rates. Following these woes surrounding the U.S. dollar, the dollar price of gold was raised to US$38 per ounce and the Bretton Woods system was modified to allow fluctuations within an augmented band of 2.25% as part of the Smithsonian Agreement signed by the G-10 members in December 1971. The agreement delayed the system's demise for a further two years. The system's erosion was expedited not only by the dollar devaluations that occurred, but also by the oil crises of the 1970s which emphasized the importance of international financial markets in petrodollar recycling and balance of payments financing. Once the world's reserve currency began to float, other nations began adopting floating exchange rate regimes.