As President Joe Biden takes up crises from Iran to Myanmar to climate change, one aspect of his approach has been strikingly consistent — seeking rock-solid cooperation with allies. After one month in the White House, it may be too soon to speak of a “Biden doctrine” but he has quickly carried out a sharp reversal of the brash “America First” philosophy of his predecessor Donald Trump, who delighted in needling friendly leaders. In his first international address, Biden vowed Friday before the virtual Munich Security Conference that he will be “in lockstep with our allies and partners.” “Let me erase any lingering doubt: The United States will work closely with our European Union partners and the capitals across the continent — from Rome to Riga — to meet the range of shared challenges we face,” he said.