17 During the period 1990-2000, local authorities had a great deal of freedom of contact and took advantage of this opportunity for paradiplomacy. For example, in 1997, the local government of Krakow reached an agreement with Grozny in Russia to show its support for the idea of independence of the Chechens (Kwiatek-So3tys, 2002). City twinning begins for many reasons. In general, twin cities have similar demographics and sizes. They can be created from business links, travel, similar industries, diaspora communities or common history. This is how the partnership between Portland, Oregon and Bologna, Italy, was born of common industries in the field of biotechnology and education and a “similar attitude towards food”, while Chicago`s link with Warsaw, Poland, with the historic Polish community of Chicago began.  The twinning between Indianapolis and Monza, Italy, is due to the long connection between the two cities and motor racing. 21 Among the international links of Polish communities, the share of border partnerships is linked to cooperation with Czech (85% of all links) and Slovak (70%) the highest. (Figure 2). This shows the frame character of these contacts. In terms of cooperation with Lithuania, only 9% of city twinnings are border-related, compared to 17% with Germany and Ukraine. The absolute number of border partnerships includes most links with partners from the Czech Republic (at least 149 routes), Germany (111 routes) and Slovakia (71 routes).
The number of twinnings on Poland`s eastern border is much lower. What physical flows (goods and infrastructure) and intangible flows (knowledge and information) result from partnership relationships? 1 It is likely that in 1918, the first twinnings recorded in Europe between Brugg (Switzerland) and Rottweil (Casagrande, cited in Zelinsky, 1991) or 1920 between Keighley, United Kingdom and Poix du Nord, France (Handley, 2001) were established. After the Second World War, the concept of twinning spread around the world and was used as an effective instrument in the peace and reconciliation process, which brings together countries that were previously trapped in the struggle.