Extremism in special education has been an endemic feature for decades but its most recent iteration, the full inclusion movement (FIM), is pushing special education toward a radical ideology in which placement in mainstream schools, rather than providing effective instruction, is becoming the main focus of efforts to meet the needs of students with special educational needs and disabilities (SEND). We first review some realities that we believe are basic to special education as it has been conceptualised and practiced. Second, we provide examples of the rhetoric of supporters of the full inclusion movement that do not conform to those realities and consequentially threaten the existence of special education. Third, we suggest a way in which special education might be transformed through the adoption of policies that conform to those realities while being based on research evidence of their effectiveness in improving outcomes and a combination of the best aspects of special education and inclusive education. We conclude that there is an urgent need to recognise this extremist threat to special education, do what we can to prevent it, and avoid its potential negative consequences.