sentences:  Upon becoming Prime Minister of South Africa, Smuts declared South Africa officially at war with Germany and the Axis.Smuts immediately set about fortifying South Africa against any possible German sea invasion because of South Africa's global strategic importance controlling the long sea route around the Cape of Good Hope.Smuts took severe action against the pro-Nazi South Africa Ossewabrandwag movement (they were caught committing acts of sabotage) and jailed its leaders for the duration of the war.