With the help of the 1951 UN Convention and Protocol Relating to the Status of Refugees (UNHCR), Vlado Fabry was eventually able to become a United States Citizen on August 31, 1959, but not without troubles along the way. For one thing, it took a while before he had work at the UN in New York that kept him in the US for the required consecutive time period – he was called all over the world. But there was also trouble from the new Czechoslovak Government, who invalidated Vlado’s passport and asked the Secretary General to dismiss Vlado from the UN.
This undated Annex was found with the naturalization papers:

Annex A
To application to file petition for naturalization
Page 2, question No. 6

I am not aware of ever having committed any crime or offense, in the United States or in any other country, except for minor traffic law violations. However, in October 1940, after having organized a mass walk-out of Slovak protestant students from a Nazi-sponsored organization called the Academic Hlinka Guard, I was arrested and without formal charge, trial or hearings of any kind condemned to deportation. On 27 January 1945, I was sentenced to death by the “Sicherheitsdienst”(Gestapo) for obstructing the German war effort and participation in the Slovak liberation movement against German occupation forces. After the Communist Party seized power in Czechoslovakia, I was charged with “anti-state activities” for having expressed anti-Communist opinions and advocating freedom of private enterprise while employed as an official of the Czechoslovak Ministry of Commerce in 1945-6. As far as I know no formal trial was held on these charges, as I refused to return to Czechoslovakia when my passport was withdrawn and the Secretary-General did not deem it fit to comply with the request of the Czechoslovak Government for my dismissal from the United Nations service.

Vlado had to return to the US from his mission in Indonesia with an invalid passport, and he gives his account in this document dated August 22, 1951, addressed to Miss Alice Ehrenfeld:

Admission to the United States.

On your request, I herewith submit to you the information which you may need to deal with the question of my admission to the United States.
I was born on 23 November 1920 as a citizen of Czechoslovakia. I have been a member of the staff of the United Nations Secretariat since 15 June 1946, serving under an indeterminate (permanent) contract.
I entered the United States for the first time on 15 June 1946 and was admitted under Section 3, paragraph 7, of the Immigration Act for the duration of my status as an International Organizations Alien. In April 1948 I left the United States on an official mission, re-entered the country on 6 January 1949 and left again on 15 February 1949 to serve with the United Nations Commission for Indonesia. After completion of my duties there, I was instructed to return to Headquarters for service with the Legal Department of the Secretariat in New York.
As a consequence of my political convictions and activities, I became a displaced person after the communist coup d’état in Czechoslovakia in February 1948. The Czechoslovak Government has ceased to recognize the validity of my passport (No. Dipl. 2030/46).
I drew the attention of the competent officer in the Department to this fact when I was leaving on my mission assignment, and I received the assurance that there would be no difficulty regarding my re-admission to the United States. This assurance had been given, I understand, after consultation with the State Department.
I also explained my case to the United States Vice Consul in Djakarta, Indonesia, who was issuing my United States visa. He advised me that it was sufficient if I held my invalid passport as an identity paper, and that no difficulty would result from the fact that my visa was not stamped in a valid passport.
Upon arrival at Idlewild Airport, New York, on 20 August 1951 (7:30 A.M.), I was told by the immigration officer on duty that I could not enter the United States. I was then requested to sign an agreement according to which I was released on parole. My passport and the Alien Registration Form on which the United States visa was stamped were taken away from me with the remark that my office should undertake further steps to regularize my status and affect the release of my documents.

Here are some images of Vlado’s United Nations Laissez-Passer (UNLP), issued to him on October 6, 1952, and signed by the first UN Secretary General Trygve Lie:

By 1954, Vlado had long been stateless, with no place to call home. He writes to Marshall Williams, Administrative Officer, Bureau of Personnel at the UN, on May 18, 1954:

Request for permission to change visa status

1. I was notified by the United States Consulate-General in Zurich that a number on the DP immigration quota became available for me and that I should present myself at the consulate in Zurich before 27 May.

2. I should be grateful to receive permission to sign a waiver of United Nations privileges and immunities, which I understand to be a condition for the granting of a permanent residence visa. I trust that such permission will not be denied as it is essential for me, for the reasons indicated below, to acquire the right to establish a home somewhere. In view of the shortness of time given to me for appearance before the consular authorities, I should appreciate it if my request could be considered as urgent.

3. I should also like to apply for the permission to change my visa status without losing entitlement to tax reimbursement. The Report on Personnel Policy adopted by the Fifth Committee during the last session of the General Assembly states that the Secretary-General should be able to grant such permission in “exceptional and compelling circumstances”. In accordance with a statement made by the Chairman of the Advisory Committee on this subject, this provision relates to “certain officials of the Secretariat who had lost their nationality through no fault of their own and who might quite legitimately seek to acquire another”. I sincerely believe that these conditions are present in my case.

4. I have lost my nationality and I am unable to return to my country of origin because of substantiated fear of persecution on account of my political opinions and activities undertaken prior to my joining the United Nations. In the years 1945-1946, I was an active member of the Slovak Democratic Party which at that time was lawfully permitted and recognized as an instrument of the political will of the majority of the Slovak people; I also held the position of Assistant (Chef de Cabinet) to the Minister of Commerce. In accordance with my beliefs and official directives, I worked to the best of my ability on fostering the resumption of normal conditions under which trade could prosper, and on preventing the suppression by force of the right to enjoy private property and freedom of enterprise; such activity, lawful and constituting part of my official duties at the time it was undertaken, is considered criminal by the regime which since has come to power in my country. I was therefore compelled to become an expatriate, or else to make myself the object of grievous persecution. My fear of persecution is substantiated by the facts that members of my family and several of my friends had been arrested and interrogated regarding my activities; and that persons who held positions similar to mine, and did not escape abroad, were sentenced to long prison terms or maltreated to death.

5. Having thus without fault of my own lost my nationality, I consider myself legitimately entitled to seek to acquire the right to establish a permanent residence, a home, in another country. For although it is true that I have the right to stay in a country as long as I remain there in the United Nations service, I must provide for the possibility, which I hope shall not occur, that I might lose my present employment (and in any case, I shall need some place where I can reside after I reach the age limit). Moreover, being stateless and without the right to permanent residence anywhere, I am subject to many restrictions and deprivations.

6. I therefore firmly believe that I have compelling reasons for obtaining a visa status authorizing my permanent residence in the United States, and I hope that I shall be granted the permission to change my visa status without losing entitlement to tax reimbursement. I feel that it would be unjust if, having lost my nationality, I should be penalized for this misfortune by being made subject to financial burdens which I can ill afford.

Here is Vlado’s passport, renewed and signed by Dag Hammarskjold:

And finally, the sought after United States Certificate of Naturalization: