In contrast to the previous period, the question of the membership of Sloveniain possible NATO, gained a new dimension in 2001-2002, since the membership became acceptable in principle, also for NATO. This requires a substantive and correct public debate. The author sees an important reason for a lack of such debate in insufficient political culture of dialog. A majority of the published articles and comments in mass media were until now one-sided. The author noticed a lot of very controversial and false statementson the part of the opponents to the NATO membership. The ruling coalition was unconcerned for a long time, while an organised campaign againstthe NATO membership has been carried out in some Slovenian mass media. Aggravating circumstances are still the wide-spread ignorance, incorrect notions and biases against NATO. The main reason for the decline in public opinion support is seen in a widespread false of feeling false security and the weakening of collective memory. The debate on NATO membership, due to several factors, has produced political polarisation, that largely cuts accross the usual social, cultural, religious, and ideological divisions in Slovenian society.