Sun Tzu's Art of War?

Considering the time Sun Tzu's art of war was based on conflicts of his time, should it be considered obsolete. My reason for asking his is because in Sun Tzu's time, there were large conflicts between nations consisting of large armies in battles, nowadays, we send in small tactical forces and special forces and equipment like aircraft, seacraft, and spacecraft. So again my question, does Sun Tzu's Art of War still apply to nowadays warfare??