This chapter will give an overview of the trend in international efforts in criminal justice,escape of offenders to foreign countries and their extradition,and international assistance in criminal investigation and justice.
  In the recent crimes in Japan,internationalization of crimes such as increasing offenses committed abroad as well as internationalization of offenders such as increasing visiting foreign national offenders has been observed.Consequently,there are a great number of offenses that require international cooperation in criminal investigation and justice such as collecting evidence abroad,arresting offenders escaped abroad and extraditing them to their home countries,and cooperation with foreign countries has developed.
  International cooperation is indispensable for properly dealing with transnational drug trafficking,terrorism,and organized crimes committed by transnational organized crime groups,and various measures have been taken to strengthen international cooperation at the United Nations and summit meetings of leading countries.Recently,in addition to international cooperation in law enforcement,positive measures also have been taken to achieve international cooperation in order to develop international standards(not limited to legal norms such as conventions)for harmonizing criminal justice systems of various countries.
  Along with the economic and social globalization,international transfer of human resources,goods,money and information facilitated by the progress in information and communication technology and transportation has caused a globalization of crimes.For instance,it has become easier to transfer offenders,firearms and drugs across national borders and to collude with accomplices abroad.Furthermore,it has become possible to transfer crime proceeds instantly across national borders for the purpose of money laundering.Cybercrimes also have been committed in the borderless realm of the Internet known as cyberspace.In order to take effective measures to deal with these modern crimes that are becoming more global in scale,it is insufficient for individual countries merely to take measures to prevent crimes in their own territories;rather,it is necessary to reduce those countries and regions in the world with lax regulations so as not to allow the havens for offenders.Based on such reco gnition,international cooperation has been promoted since the1990s with the aim of harmonizing criminal justice systems at various international forums such as the United Nations and summit meetings of leading countries.