In the first book, Aragorn and the Hobbits set up camp and start a fire on the side of Weathertop. Why is stealth no longer necessary? Between setting off from the Shire and reaching Weathertop, the party goes to great lengths and faces many dangers and unknowns just to avoid being found by the Nazgûl. A fire makes light and smoke revealing their position. Unsurprisingly, the Nazgûl soon find and attack them.
Aragorn appears to do a 180: one moment, he still cares about stealth "I was too careless on the hill-top ... it was a mistake for three of us to go up and stand there for so long", but the next moment, he suggests starting a fire. Note that at this point, there is no indication that they have been spotted. Sam correctly points out that fire equals no stealth, but there is no response.
All the justification we get is:
Aragorn: Let us take this wood that is set ready for fire as a sign. There is little shelter or defense here, but fire shall serve us both. Sauron can put fire to his evil uses, as he can all things, but the Riders do not love it, and fear those who wield it. Fire is our friend in the wilderness.
I do not understand this. What is Aragorn's plan? Is he counting on remaining hidden, despite the fire? Has he given up on stealth? Why? Is he counting on being able to fight off the Nazgûl? The same Nazgûl who battled Gandalf a couple of nights prior? Did Aragorn not know how powerful they are?