share: digg facebook twitter Worries about the economy in Europe and China helped support the dollar, which traders have traditionally considered a safe haven during periods of geopolitical tensions or concerns about the health of the global recovery from the recession. Brown Brothers Harriman currency analysts said investors are concerned about the fate of a second round of emergency aid needed to keep Greece from defaulting on its debt. The credit ratings agency Standard & Poor's warned on Monday that a plan backed by European politicians to include private-sector lenders in the new aid package would likely be a default.