made public preparations for a strike against the City if it challenged the union's right to represent these employees or to roll back their contract rights. La Guardia responded by directing the Police Department to develop plans to run the subways in the event of a strike and supporting legislation that made it a crime for workers to leave transit equipment unattended. La Guardia went further and announced that while workers could choose organizations to represent them, the City had no obligation to recognize those organizations as the exclusive representative of those workers or to engage in collective bargaining with them. In the end the adversaries resolved their differences, but in a very ambiguous way, through intermediaries, without actually settling the key issues. With the intervention of the Roosevelt administration and the national leadership of the CIO, the City agreed, in a series of telegrams exchanged in June, 1941 between LaGuardia and Philip Murray of the CIO, to maintain the status quo under the collective bargaining agreements with the TWU that the City had assumed, while agreeing to disagree as to whether they would bargain in the future. The parties also differed on practical details: the City took the position that promotions would be made according to Civil Service requirements, the CIO took the position that seniority provisions would still govern. The union not only survived, but regained much of the ground it had lost among transit workers during the next four years. Internal and external pressures At the same time that the union was fighting La Guardia, it found itself challenged by dissidents within the union and the Association of Catholic Trade Unionists and rival unions outside it. The CPUSA's dominant position within its officialdom and staff was the galvanizing issue. Quill and the union leadership gave their opponents all the ammunition they needed by following the changes in the CPUSA's foreign policy, moving to a militant policy after the Molotov-Ribbentrop pact in 1939, then coming out against strikes after the Nazi invasion of the Soviet Union in 1941. The United States' entry into the war, however, largely smoothed over many of these differences, even narrowing the union's differences with the La Guardia administration by restoring the grand Popular Front coalition to some of its former influence. Quill disposed of his internal critics by bringing union charges against more than a hundred opponents. The union also drove off a