Why did the U.S. place an arms embargo on all belligerents in the 1948 Arab-Israeli war? My understanding is that it hindered Israel more and forced them to buy weapons from Czechoslovakia. Most people don't know this, but the Soviet Union was the first country to help the nascent Jewish state. https://www.haaretz.com/1.4904990
Question: Why did the U.S. place an arms embargo on all belligerents in the 1948 Arab-Israeli war?
The United States cut off weapons shipments to the region 5 months prior to the hostilities breaking out Dec 5, 1947. It did so because the United States a few days earlier had just helped negotiate a partition agreement UN Resolution 181(III) Nov 29th 1947 in the General Assemble. Part of that resolution called for the UN Security Council to secure the peace. This coincided with the US's discontinuing export licenses of arms December 5 not a formal embargo.
Now in addition to the US discontinuing export licensing of arms in 1947, The United States also participated in the United Nations arms embargo in June of 1948. This embargo coincided with a UN negotiated cease fire in the conflict and the embargo was designed to ensure neither side used the cease fire to improve their strategic position.
The US primary motivation in it's action in 1947 - 49 was to secure a negotiated peace in the ME through the United Nations and then directly after hostilities began. When War broke out the US's efforts focused on brokering an Armistice; which the American Ralph Bunche successfully negotiated in 1949, after the assassination of his predecessor, for which Mr. Bunche received the Nobel Peace Prize in 1950.
- Nov 29, 1947 the UN General Assembly adopts a partition plan Resolution 181 (II)
- Dec 5th, 1947 The United States discontinued the export licensing of arms to Palestine and neighboring Countries as part of Resolution (ll).
- May 14, 1948 Israel declares itself a state.
- May 14, 1948 The United States becomes the first country to recognize Israel, about 2 hours after it's declaration
- May 15 1948 The Arab Israeli war begins
- June 11 – July 9 1948 UN Embargo of Arms to Palestine and Neighboring Countries coincides with a UN negotiated cease fire.
- Sept 17, 1948 Swedish UN Envoy Folke Bernadotte assassinated in Jerusalem by members of the underground Jewish Lehi group, which was led by Yitzhak Shamir as Bennadotte was negotiating an armistice agreement.
- March 10 1949 The Arab Israeli War ends..
- 1950 - The African American Ralph Bunche receives Nobel Peace Prize in 1950 for continuing Folke Bernadotte's work and successfully negotiating the 1949 Armistice.
This is quite complicated but from the information I found online it looks like the US in 1947 had two reasons for having an embargo. This is from an article called Arms and Influence: British arms policy and the decline of British influence in the Middle East, 1948-49
Following World War II, the US government adopted a policy of providing very limited arms supplies to the Middle East, usually small quantities for internal security purposes only.30 During the course of Anglo-American military talks, known as the “Pentagon Talks”31 held in October and November 1947, the United States acknowledged Britain’s dominate influence in the Middle East.32 In November 1947 the State Department decided to impose a unilateral arms embargo on the Middle East to prevent the Arabs using “arms of US origin against Jews, or Jews using them against Arabs” to prevent bitter recrimination against the USA.33 The embargo became public policy after the State Department issued a statement on 5 December 1947, which included a detailed breakdown of the inconsequential US arms supplies to the region.34
So it looks like the US didn't want to take sides and wanted to not get involved as the British were more established in the region. And the US was also worried about the future and oil. There's anotherarticle called U.S. Policy in Israel/Palestine, 1948: The Forgotten History which says more about this, and that there were also disagreements in the US adminstration about what to do.