basque nationalist party -lrb- pnv -rrb- chairman xabier arzalluz stated in a speech delivered during the aberri eguna -lsb- basque fatherland day -rsb- celebrations that his party will not confine its political demands to the autonomy statute , that the pnv claims sovereignty for all the basque territories , and that the basque country will `` gradually '' achieve a `` cultural , economic , and ultimately political unity in europe , '' as well as asserting that the constitution entrusts the defense of spain 's unity to the army and violence .