One effect of having to continuously defend itself against either actual or potential war/attacks has been the creation of the Israel Defence Force (IDF), the Haganah. They received major help from two British officers, Lt Col JH Patterson, who, after World War 1, dedicated himself to assisting with the creation of a Jewish homeland in Palestine and Captain (later Major General) Orde Wingate who developed and trained the Special Night Squads (SNS) of British soldiers and Jewish volunteers to ambush Arab saboteurs carrying out terror and guerilla raids.
Today, there is conscription for Israeli citizens over 18. Exemption is given to non-Druze Arab, or other, citizens on religious, physical or psychological grounds. The normal length of compulsory service is three years for men and two years for women. On completion they join the Reserve Army to the age of 40 for soldiers, 45 for officers, and 49 for some others.
The effect of having to concentrate on defence is shown by Stockholm International Peace Research Institute. This shows that in 2014 Israel spent 5.4% of its Gross Domestic Product (national income) on defence compared to 2.0% in the UK and 3.3% in the USA.