Canada and UN: How do you start a intro paragraph in a persuasive essay?

I got a Intro paragraph and the three points. I got all the facts I want to write on about on the first and second paragraphs but I don't know how to start my first paragraph. Here is my thesis.

Canada has been activity involved with the United Nations since its creation in 1945. Since then Canadian peacekeepers have participated in almost every single peacekeeping mission. The role of Canadian peacekeeping was to bring peace and stability between warring countries. But until now Canada's role in the United Nations is slowly starting to diminish and because of that Canadian Peacekeeping has become ineffective because of its failure to prevent conflict in Yugoslavia, stop the civil war in Somalia and to interfere with the mass genocide in Rwanda.

How should I start with my first paragraph?

try to combine the second and third sentence it seems a bit repetative

But until now Canada's role in the United Nations is slowly starting to diminish ...
wait a minute! What does this mean? Is it an error?
Maybe you mean to write:
In recent years, however, Canada's role in the UN is starting to diminish...

The way to start the first body para is with a topic sentence that makes one of your 3 points. The topic sentence is followed by a sentence that elaborates or explains a little. Then. give a sentence that has an example or quote. Finally, finish the para with a sentence that evaluates what you just said or that reflects on its implications.

Do that for every para!! It's a good recipe.

:-)