By JOHN LEICESTER
PARIS (AP) — Russian President Vladimir Putin’s war in Ukraine is causing a swift and broad decaying of scientific ties between Moscow and the West. Post-Cold War bridge-building through shared science is unraveling as Western nations seek to punish and isolate the Kremlin by drying up support for scientific programs involving Russia. Scientists say the costs of this decoupling could be high on both sides and that picking apart the dense web of relationships will be complicated. Climate scientists worry how they’ll keep up their important work of documenting warming in the Arctic without Russian help. And Europe’s space agency is wrestling with how its planned Mars rover might survive freezing nights on Mars without its Russian heating unit.