Israel is quietly allowing thousands of Palestinians to enter from the Gaza Strip to work, apparently as part of understandings with the ruling Hamas militant group aimed at preventing a fourth war in the blockaded territory. Israel effectively revoked thousands of work permits when it joined Egypt in imposing a crippling blockade on Gaza after Hamas seized power in the coastal strip from rival Palestinian forces in 2007. The blockade, along with three wars between Hamas and Israel, has devastated the economy in Gaza, where unemployment is over 50 percent. But in recent months, Israel has quietly provided some relief as part of an unofficial, Egyptian-brokered truce with Hamas, in exchange for reduced rocket fire from the territory and the scaling back of weekly protests along the border.