OBEDJIWAN, Canada — An out-of-control fire was advancing rapidly toward a logging road on Tuesday afternoon, tearing through Canada’s immense — and highly flammable — boreal forest with a force and intensity bewildering to a team of French firefighters. Surrounded by thick smoke, a handful of them headed into the forest to search for water. A veteran knelt down and used his right finger to sketch a plan on the gravel road, pressing to attack the fire head-on. But the commander was not convinced.