premise: Rehab was successful in multiple countries.
hypothesis: Rehab (Amy Winehouse song) . `` Rehab '' was released as the lead single from Back to Black on 23 October 2006 , and it peaked at number 7 in the United Kingdom on its Singles Chart and number 9 in the United States on the Billboard Hot 100 , becoming Winehouse 's only top 10 hit in the US . `` Rehab '' has become a critical and commercial success internationally , and has been referred to as Winehouse 's `` signature song '' . Rehab (Rihanna song) . `` Rehab '' reached top-ten positions on the singles charts in Austria , Germany , the Netherlands and Norway . A world war , as it is commonly understood , is a large-scale war involving many of the countries of the world or many of the most powerful and populous ones .