\begin{tikzpicture}
    \node[align=center] (eq) at (0,0) {Imposer\\l'équité};
    \node[align=center] (aia) at (-6,0) {Protection\\contre\\AIA};
    \node[align=center] (mia) at (6,0) {Protection\\contre\\MIA};

    \draw[olive] (aia) -- node[above] (ali) {Alignement ?} (eq);
    \draw[red] (mia) -- node[above] {Conflit} (eq);

    \node[align=center] (algo) at (-5,2) {\emph{Contribution 1 :} \\{\emph{Nouvelle AIA}}};
    \draw (algo) -- (aia);
    

    \node[align=center] (theo) at (-2,-2) {Contribution 2 : \\\begin{minipage}{100px}\centering{Etude théorique de cet alignement}\end{minipage}};
    \draw (theo) -- (ali);
     

    \node[align=center] (synth) at (2,2) {Contribution 3 :\\ \begin{minipage}{100px}\centering{Vers une protection contre AIA et MIA}\end{minipage}};
    \draw (synth) -- (aia);
    \draw (synth) -- (mia);


\end{tikzpicture}