The Iran war and lingering trade tensions could dent euro zone economic growth, push up ‌borrowing costs and challenge some member states' ability to sustain public budgets, a European Central Bank report concluded on Wednesday. Financial markets have mostly shrugged off the war in Iran, leaving stocks at rich valuations, corporate borrowing costs low and ​the spread between sovereign bond yields across the 21-nation bloc at low levels, raising fears that ​investors may be complacent about risks. [....]