The dividing of Ireland between the Irish Free State and Northern Ireland was not as controversial. One of the main reasons for this was that Collins was secretly planning to launch a guerrilla war against the Northern State. In the early months of 1922, he had sent IRA units to the border, and arms and money to the northern units. In May–June 1922, he and IRA Chief of Staff Liam Lynch organised an attack of both pro- and anti-treaty IRA units along the new border. This offensive was officially called off under British pressure on 3 June and Collins issued a statement that "no troops from the 26 counties, either those under official control [pro-treaty] or those attached to the [IRA] Executive [anti-treaty] should be permitted to invade the six county area."