A new round of attacks in the Iran war this week sent energy prices soaring again, intensifying the sell-off in global bond markets and pushing up government borrowing costs. Investors are bracing for a series of potential interest rate hikes from the Federal Reserve, the European Central Bank, and the Bank of Japan this month. Federal Reserve Governor Barr hinted on Tuesday that a rate hike might be necessary in September, and Chairman Warsh also articulated the rationale for a hike last week. The Reserve Bank of New Zealand has already taken action, raising rates for the second consecutive time on Wednesday.