was surprised at the Irish reaction, which might influence Irish Americans to bring the United States into the war. Although there was a later raid on 4 May, it was confined to the docks and shipyards (see Belfast blitz). Ireland wanted to maintain a public stance of neutrality and refused to close the German and Japanese embassies. Unlike many other non-combatant states, Ireland did not declare war on the near-defeated Germany, and therefore did not seize any German assets. Other neutral countries like Sweden and Switzerland expelled German embassy staff at the end of the war, as they no longer represented a state, but the German legation in Dublin was allowed to remain open. Irish neutrality during the war was threatened from within by the Irish Republican Army (IRA), which sought to provoke a confrontation between Britain and Ireland. This plan collapsed, however, when IRA chief of staff Seán Russell died in a U-boat off the Irish coast as part of Operation Dove; the Germans also later came to realise they had overestimated the capabilities of the IRA. The American ambassador, David Gray, stated that he once asked de Valera, early in the war, what he would do if German paratroopers "liberated" Derry. According to Gray, de Valera was silent for a time and then replied "I don't know." De Valera viewed the IRA threat to the authority of the state as sufficiently significant to intern 5,000 IRA members without trial at the Curragh Camp for the duration of the war. In 1966, a forest in Israel was planted in Éamon de Valera's honour at Kfar Kana near Nazareth. Many German spies were sent to Ireland, but all were captured quickly as a result of good intelligence and sometimes their ineptitude. The chief Abwehr spy was Hermann Görtz. In 1983, RTÉ made Caught in a Free State, a dramatised television series about Görtz and his fellow spies. As the state was neutral, Irish cargo ships continued to sail with full navigation lights. They had large tricolours and the word "EIRE" painted large on their sides and decks. At that time, Allied ships travelled in convoy for protection from the U-boat wolfpacks. If a ship was torpedoed, it was left behind since the other ships could not stop for fear of becoming a target themselves. Irish ships often stopped, and they rescued more than 500 seamen, and some airmen, from many