BRUSSELS (AFP) - Former Dutch foreign minister Jaap de Hoop Scheffer took over as NATO head pledging to act with "vigour" at a crucial time for the alliance, as it faces key challenges in Afghanistan and possibly Iraq. Keeping US-Europe relations on an even keel will be a key priority, he said Monday, while adding that bolstering a NATO-led peacekeeping force in Afghanistan must be the alliance's "primary focus" for the moment. "There will be no lack of challenges.." said De Hoop Scheffer as he arrived for his first day of work at the alliance's Brussels headquarters adding that he...