Forest Fire Prevention
Early efforts at forest fire prevents took as a baseline assumption that all forest fires are bad. They systematically attempted to identify fires (often with "fire towers" manned twenty-four hours by lonely observers), and then attempted to suppress forest fires as soon as they were located. The policy was maintained for roughly a century with a great deal of success in meeting its objectives.
Around the mid to late 20th century, however, as the study of ecology as a discipline advanced and the environmental movement began rethinking the relationship between man and the natural world this philosophy changed.
Ecologists explained that forest fires, often caused by lightning, are natural and have been happening for millions of years on a regular basis. They noted that periodic small fires clear out underbrush and leaf litter, allow larger trees to grow, preventing larger fires from errupting, and in some species, are actually necessary for the plant to reproduce. This isn't to say that ecologists actually endorsed forest fires. They were also well aware that man made events cause a large percentage of all forest fires, which takes the natural environment out of balance, and that forest fires and human habitations don't mix well.
From this wisdom has come a new philosophy of forest fire prevention. This philosophy only selectively tries to stops forest fires from burning, primarily when they are caused by people or when they threaten human habitations. At times, this philosophy actually calls for forest managers to start controlled forest fires themselves, in order to make up for the effects of an absence of forest fires during the period when forest fires were actively suppressed, and to prevent uncontrolled fires from igniting near human habitations.
Much of the land vulnerable to forest fires is owned by the government. These Public Lands are managed by government officials. These government officials would like to carry out a forest fire prevention program with a modern philosophy, but also have limited budgets and must respond to the political interests of the Forestry industry (i.e. timber companies) who have historically been permitted by Congress to cut timber on public lands in exchange for modest fees. One way of balancing these competing demands has been to have timber companies "thin" forests to prevent forest fires in exchange for being able to take lumber from those forests for their own uses.
The problem with this "win win" solution is that timber companies need to cut mature trees, often far from human habitations, to be profitable, while the main forest fire threats come from unmarketable brush and scrubby trees near human habitations. The administration of George W. Bush has resolved this conflict as a matter of policy, by favoring timber company interests over sound forest fire prevention policies.