joined the invasion
...that 17 days after the Germans invaded Poland in 1939, the Soviet Union joined the invasion, ensuring the fall of the Second Polish Republic?
...that 17<span id="mwBqs" typeof="mw:Entity"> </span>days after the <a class="mw-redirect" href="./Invasion_of_Poland_(1939)" id="mwBqw" rel="mw:WikiLink" title="Invasion of Poland (1939)">Germans invaded Poland</a> in 1939, the <a href="./Soviet_Union" id="mwBq0" rel="mw:WikiLink" title="Soviet Union">Soviet Union</a> <b id="mwBq4"><a class="mw-redirect" href="./Soviet_invasion_of_Poland_(1939)" id="mwBq8" rel="mw:WikiLink" title="Soviet invasion of Poland (1939)">joined the invasion</a></b>, ensuring the fall of the <a href="./Second_Polish_Republic" id="mwBrA" rel="mw:WikiLink" title="Second Polish Republic">Second Polish Republic</a>?