Simple sentences, adverbial clauses

I need some help with the following exercise :

1. Break the passage into as many simple sentences as possible, making a separate sentence out of any general adverbial clause that can stand alone.
2. Recombine those simple sentences which logically fit together.

There has been a substantive change in the nature of the conditions that determine the complex fabric of international security. In this scenario of great changes, if the United Nations wishes to remain faithful to the purposes and principles that presided over its birth and thus constitute a useful instrument of peace and harmonious development for the planet, rather than a merely symbolic institution, the Organization will undertake a profound renewal of its structures in order to achieve the efficiency that all countries of the world are clearly calling for.