Sino-Japanese relations have developed over time from the normalization of diplomatic relations in the 1970s to current economic and security issues. Key events included PM Tanaka establishing full diplomatic ties in 1972 based on recognizing each other's governments and abandoning claims to Taiwan. Economic relations grew significantly from the 1970s onward through trade agreements and Japan becoming a top investor in China. However, territorial disputes over islands and maritime security issues periodically strain relations.