Tensions continue to escalate between the Spanish central government and Catalonia's regional government. Madrid is increasing legal, economic and political pressure over Catalan authorities in an effort to disrupt the organization of an independence referendum on Oct. 1. On Sept. 20, Spanish police entered several Catalan government offices in Barcelona, seized documentation related to the referendum and arrested at least a dozen Catalan government officials. In response, thousands of pro-independence demonstrators took to the streets in Barcelona to protest....