A law passed in 1947 that tilted the balance of power a little more toward business and away from unions following the pro-union laws passed in the first half of the 1900s. The legislation authorized the U.S. president to obtain an injunction to postpone a strike if it would hurt the economic interests of the country. This right has been invoked or threatened in recent years for strikes against airlines. The legislation also gives states the right to enact right-to-work laws, which prohibit unions from requiring union membership as a condition of employment. The law also contains disclosure requirements to regulate union business dealings and to discover fraud and racketeering and places a variety of other restrictions on unions.