Given the established global supply chains, Japanese manufacturers have divided their production at home and abroad as follows: (1) overseas sites  11  producing for their own local market and for export to third countries, and (2) Japanese sites producing for Japan's domestic market.
This division has likely resulted in a mitigated adverse effect that a slowdown in external demand would have on Japan's GDP through a decrease in exports. Given the geopolitical background to the U.S.-China trade conflict, it is entirely possible, depending on future developments, that existing global supply chains may be reorganized, particularly with respect to China.