• Commitment comes at 'coalition of willing' gathering • Security protocols 'as strong as anyone has ever seen,' Witkoff says • Guarantees would enter into force after ceasefire • Question mark hangs over Russian response The United States for the first time on Tuesday backed a broad coalition of Ukraine's allies vowing to provide security guarantees that leaders said would include binding commitments to support the country if Russia attacks again. The pledge came at a summit in Paris of the "coalition of the willing" of mainly European nations to firm up guarantees to reassure Kyiv in the event of...