25 April 1961
On 25 April 1961, France conducted its fourth nuclear bomb  test in the Sahara Desert. Adding to the tension of the time, was an underlyingFrench ambition to lead Europe and potentially become a superpower in its own right. This ambition was thwarted by the creation of the North Atlantic Treaty Organisation and the position occupied by Britain and the United States in this military alliance. This situation was further complicated by the loss of Algeria, a French colony. Further, France had lost faith in her British and American allies to defend French interests, after the United States compelled Britain and France to withdraw their troops after the Suez Canal crisis. Thus, producing and testing an indigenous nuclear capability was vital to France maintaining its position and prestige in Western Europe. The fourth nuclear bomb test by France in the Sahara was thus symbolic in that it demonstrated the prestige that France retained despite being diminished by two World Wars.
References

This day in African History: 25 April (online), available at: africanhistory.about.com [Accessed 20 April 2010]| French soldiers 'deliberately exposed' to nuclear tests (online), available at: news.bbc.co.uk [Accessed 20 April 2010]| Zoppo.C.E.(1962), France as a Nuclear power (online), available at: rand.org [Accessed 20 April 2010]